Marvels reason for that is they want people to concentrate on the characters, not the voices...if you look at any of their DTVs, its all people who are dedicated voice actors
That isn't to say that Marvel's animated voice casts are in any way bad. I didn't intend it that way. It's just they usually are lower profile, and in a way that is a shame. One easy example is Nolan North. He's played a variety of roles for them lately; Hank Pym in ULTIMATE AVENGERS 1 & 2, Deadpool in HULK VS. WOLVERINE, and naturally Cyclops in WOLVERINE AND THE X-MEN. Back in 2007, WB put out their CGI "TMNT" film, and North starred as Raph. "Starred" is the appropriate term. Raph probably has more lines than the rest of the characters, and clearly has the strongest growth of the film, as he has to learn to not only forgive Leo for leaving their family, but get used to working with his brothers again. Yet does North get top billing? No. Y'know who does? Kevin Smith, who had, at best, a 3-5 line cameo (which in the commentary is stated to have been mostly improved). That's woefully unfair. In some ways "UP" had the same problem. Ed Asner was the star. But his name wasn't as plastered all over the place, either. If Ryan Seacrest had a cameo,
his would have.
But, I digress. To be fair, SPECTACULAR SPIDER-MAN actually had some modest "celeb" casting as it went along. Granted, it's a Greg Wiesman production, and he always lines up talent. He even got a few larger profile actors for a dub of the anime 3X3 EYES some years back.
My point was that usually the WB stuff has more of a casting budget, not that the performances are better. Although I will say that Andrea Romano is an excellent director and even "celeb" parts for the DTV's are usually well cast. They're not as bad as, say, some of the celebrity casting in some bigger budget motion pictures that Disney and WB did, especially in the late 90's. HOME ON THE RANGE, anyone?
Hell, the voice cast of WOLVERINE AND THE X-MEN is one of it's strengths. It usually pleasantly distracts from some of the writing hiccups.
It was just something I'd noticed.