I wouldn't call it a "cheat" if no code was changed or altered mechanics etc.
I would call it an "exploit" as it seems against what the devs want since they removed the ability to level up shooting rocks.

No one is going to care honestly. They are only cheating themselves out of the proper game experience. But that is up to them as much as using the console or mods.

Personally I don't do it and call it cheese. Although I am not above cheesing bosses, I don't want to do it for my skills. I like to analyse progression systems in games and that would ruin it for me.