Re: "Joyless" ?
Again, Jon Kent had valid concerns that the exposure of his son's existence would have drastic consequences for THE ENTIRE WORLD, many of the permutations which he knew he could not see, but he did know a lot of them would be negative, both for Clark AND the wider world. See the responsibiity of that as a more than likely outcome was what Jon was trying to put off as long as he could, and for the sake of his son and the world he was willing to die. Yes they could have written it like a Silver Age story and just have Clark use "super speed faster than the eye could see" to save people. But they didn't go for such a simpleminded (but no less valid) approach to the character. They presented a world where there was no idealized 3rd option. They went for a story that took the possible consequences of it's core concept seriously as one could in an action/adventure summer tentpole film.
Finally, I gladly admit what I am going to type is itself perhaps a difference without a distinction. I owe up to that 100%, but it's how I see things. People are using "suicide" to describe the twister scene, most likely because it is a very charged word with strong negative emotions attached to it. Perhaps this is reflective of peoples view of taking ones life in real life more than it is representative of what happens in the twister scene. For those that have a positive view of MOS I think the term we would substitute is sacrifice. And, yes, to my mind self sacrifice, even unto death is noble and heroic.
I don't expect all to agree with my views nor am I presenting them as some absolute truth that you must accede to. I will say I think I have been cordial in presenting them and I hope you can see a rational and intuitive arguement being made by myself.