Modifying the game to ease playing is forbidden.
Why would someone else care of your opinion? People play these games mainly for themselves. How is bombing the attacks more of a merit, though?
Who even is the one who decides what is forbidden and what isn't? lol, if I play "for myself" I can do anything I want, and if people played only for themselves they wouldn't care about others using cheats. I certainly get mixed feelings when people brag about an achievement having abused such a bug. It is just as game breaking as using an outside alteration, period, the only difference is that one seems to be accepted by the majority because it already exists in game, which doesn't make much sense but whatever. I know that it won't change the fact that bugs will still be accepted in competitions and other things won't, I'm just stating my opinion on why I think bugs and patches and outside exploits are no different in essence. But there's no point in talking about anything ever if everyone is just going to say "I don't care about your opinion". Opinions almost never convince other people, so saying that you don't care is unnecessary and even rude sometimes.
About the merit thing, I mean merely 1ccing a game legitly, which is most people's main objective. The games were designed with lots of bombing in mind, not perfecting everything, or else they wouldn't give you tons of lives and bombs. If things were so simple to everyone as to "bomb everything" there wouldn't be tons of people struggling to 1cc. Sometimes even bombing is not an easy thing to do, as you become afraid to spend resources unnecessarily and end up dying with bombs, or you panic bomb too much and don't have bombs when you really need them.
A super-power bug obviously makes the game so much easier that you don't need to dodge and bomb as much, and everybody knows it's unintended and broken. So yes, I believe there's more merit in bombing everything legitly than abusing an overpowered bug, as bombs are limited (even in MoF). Unfortunately it's accepted by the community as something legit, and even if it was forbidden it would be impossible to avoid it completely unless Marisa B was banned as a whole.
Meh, I cut about 2/3 of my original post as it was too extensive and I don't feel like this discussion is healthy to get into too many useless details.
Regarding safespots specifically, they are legit to me, because that's just the way the patterns were made and how the bullets move; some safespots may even have been intended, and lots of them aren't that useful or easy to use anyway. It would only be an exploit if you could somehow stay in a specific spot and touch bullets without dying . It's different from like skipping bosses in SA, that's definitely a bug and totally cheating.