Sorry, we're going to have to disagree on that first statement. Comic book adaptations, and I mean super hero adaptations in particular, were still mired in the misconceptions that they were campy fare meant only for kids, parents of kids, and comic book readers. They were not four-quadrant ideas back then. It was a different world, and the instant flavor-recognition that we see with the MCU didn't exist. Studios had a lot of hurdles with which to deal.
While it might seem like a project like Spawn should be obviously in it's content, it wasn't. TMNT '90 caused controversy with its use of martial arts weaponry and and, at least in parts, brutal violence. The result of this was the comparatively tame, and less successful, TMNT 2. Batman Returns caused controversy with parents groups due to the Penguin's nose bite. Spawn, who had already been the subject of controversy on a much smaller scale due to the comic content, saw that amplified when the movie's content became news.
So while there were the occasional outliers like Men in Black, which only had the occasional media mentions of being a comic adaptation, it was a confusing time for studios in trying to bring legendary characters from Marvel and DC to life. It was complicated--very complicated. The odds against Blade's success were long indeed, but it beat them. Here's a good article on what I mean:
An unsung hero: How Blade helped save the comic-book movie
The actual facts reported in that article are that Batman and Robin, Steel and Spawn were failures and that the creators of Blade never even considered - nor were pushed by anyone else in the studios to consider - the idea of not making the movie (or even seriously toning it down) just because of those failures. Even when one of them said he was 'worried', he explicitly adds that Mike de Luca (the guy he's working with) produced both Spawn and Steel, which would clearly seem to have more to do with that than with the viability of cbms in general. And the article also describes Spawn and Steel as worrying for Blade because both Spawn and Steel were cbms with black leads, which also goes against the narrative of cbms being unsupportable in general - but that seems to be the writer's own addition with no quote from anyone actually involved so it could be a totally irrelevant fact that the actual filmmakers never worried about at all.
All statements like 'comic book movies were being read their last rites' or that blade 'revived' or 'rebuilt' the genre are completely hollow insertions of the writer's personal belief with no facts backing them up whatsoever other than that three specific movies failed and Blade didn't. There's nothing at all in there to actually support the idea that 1997 was somehow a fundamentally worse year for these films than ever before. Because it wasn't.
Batman and Robin wasn't even a box office bomb to begin with - it probably didn't make a profit, since the budget was actually 125m for some reason and that doesn't even count all sorts of other marketing and distribution costs, but it still brought in 240m in box office. Spawn's 90m gross may have actually made a tiny profit in the end, based on the numbers, though the exact numbers of its budget seem unavailable.
Men in Black was a massive hit, which the article even acknowledges, though in a backhanded way seemingly trying to wave that fact away as an irrelevant anomaly - and yet, there had never been another cbm as successful as MiB was, and there had been LOTS of years in which there was NO cbm movie that was successful at all. So how could that possibly be the moment in which 'Comic book movies were being read their last rites'?
And there had been previous years with multiple bombs, too (Barb Wire, The Phantom, The Crow: City of Angels, Judge Dredd, Tank Girl, etc).
The worst thing you can say about 1997 is it ended the power of the current 'sure thing' in the genre (Batman), but that had happened before, too, with Superman IV.
I also have to wonder if there's been any creative editing of this interview going on looking at Frankfurt's statement that:
"I think they as well as most acknowledge that it was the first movie that kind of presented a comic-book hero in a fresh way. It made people, especially young people, pay attention and say, 'Oh wow, this could actually be cool. This could actually be something that I'd want to watch.'"
This makes perfect sense if he was referring specifically to Marvel movies (which had achieved jack **** as of that point in time), yet the article tries to make it sound like he's saying Blade was the first comic book movie to do anything different since Superman first came out, which would obviously be nonsensical.
As for the rest of your post:
1. Of course the genre was mired in perceptions of being 'kiddy' and/or 'campy'. It *always had been*. Sure, one could argue that Blade (along with X-men and others) helped change that, but that has nothing whatsoever to do with the claim that CBMs were dead in the water and wouldn't have been made anymore if Blade hadn't succeeded against all odds.
2. There is no logical defense for any studio *not* expecting some kind of pushback on a movie like Spawn. All the stuff you're saying about TMNT and Batman Returns only makes it an *even more ridiculous* concept. They could clearly already see that violence could cause controversy and even the slightest view of the source material clearly shows it could not possibly be made without serious violence couched in far more disturbing concepts and ideas than anything that was ever in TMNT or Batman. And Blade itself proves pretty clearly that violence and the controversy around it had nothing to do with why Spawn failed, anyway. Nor did that controversy do anything whatsover to stop Blade from being made.
3. This is probably an anecdotal issue where we simply came from different experiences, but my memory of the 90s as someone not following comic book fandom or internet discussions is that Blade was not really commonly referred to as a cbm, either. Not much moreso than MiB, in any case. Most people seemed to talk about it as a vampire movie or a vampire hunter movie or just a general action/horror movie.
4. The odds of CBMs succeeding were always comparatively low back then. That also has nothing to do with whether the CBM genre was ever actually on its death bed as a result of B&R or whether Blade somehow saved the entire idea of the comic book movie from oblivion and I still see no evidence that either of those things is true.
