I think you're extremely wrong about lives. Lives serve a very important purpose. You can, easily, get a lucky break on portions of levels that are otherwise challenging, only to hit a wall where you can't beat a section in order to progress because you never learned what those previous areas were trying to teach you. If you consistently fail at a single challenge, there's a solid chance it's because you failed to grasp how the game works or how a challenge is supposed to work. I've seen many a YouTube video where someone manages to skip easier sections of maps only to hit a hard point and say "this is bullshit" when they aren't actually engaging with the level in the first place. Having a hard restart to force you to re-learn things is a strong benefit and saying "lives are obsolete because they're old arcade things" isn't actually an argument. Spending extra time on a map may not actually be a waste.
I'm of the opinion that the old save method provides a similar benefit by going back to the first act, but it's also very clear that people play the game in small bursts so it's a bigger detriment than benefit.
This is basically how I feel about things. I have a
strong disagreement with the entire premise of the "Lives are a relic of the past from arcade cabinets eating up your quarters" I have seen people throwing around since Crash N.Sane came out in general. I'm fine with certain genre's not using lives systems, but most platformers benefit from such a system, as running and jumping on it's own is rather dull and boring. It's the challenge that provides the entertainment value, and punishment that provides the incentive to improve. There's no value in getting to the end with infinite tries because assuming you never give up, there's a 100% chance of you doing so.
I feel the same way about starting at the beginning of an act after a game over. Especially in a platformer like SRB2 with more than one way to get through each level even as the same character. It gives you not only the opportunity to improve and rethink your approach, but also the opportunity to take a different pathway and explore some areas you missed the chance to before, perhaps even have an easier time.
Even for experienced veterans, it's not really difficult to go and get into other things for months or even years at a time, get rusty, and find that now the game is kicking your ass when you get back. This is especially the case when level layouts are no longer what you remember, new zones are added, and therefore you can't rely on old muscle memories to be your backup guide.
Overall, I feel like the argument that gets thrown around a lot of "This doesn't effect you so you shouldn't care" isn't really entirely truthful, and kinda feels to me like saying "You don't deserve to have a say in this because I can't think of a reason this would ever impact you as a player".
I can understand making this change as a "quick" fix as Mystic put it, but I don't believe it should be a permanent one. If there is an unwillingness to compromise and implement options to make the game more punishing for those who want it, then I really hope something else gets figured out.
To finish this post off, I just want to caution against stereotyping players of any level of experience and using that as a basis to discredit their say in feedback to any sort of change like this. Even if a change is more likely to impact players of a certain skill level than others, that doesn't mean that their opinions are the only ones that matter, or that a majority of them even feel the way those you have interfaced with directly do. I feel as though this controversy is evidence (Not to be confused with proof) that the development mentality is starting to shift focus in a way that has potential to alienate long time fans of the game to bring in new players.