Game companies shouldn't change the gameplay for everyone else because others decide to play dishonestly.
I agree, but this isn't like
Mario Kart, where you basically only have to worry about that sort of thing when playing with random players (a bad idea in many online multiplayer games for one reason or another; in Nintendo's online stuff, the reason is rampant cheating). In
Pokémon, where the vast majority of serious players play this way, putting everyone else (the players who don't, won't, or can't) on an even playing field is a good thing.
I'm aware that this was possible. It just goes to show that, before unlimited TMs, you had to be extremely dedicated if you wanted to make the best team you can.
The method I described is incredibly inconvenient at best and an absolute slog at worst - neither of which are things you should want in a game. It's the wrong sort of dedication.
Wavedashing in Super Smash Bros. Melee
Wavedashing is a bad example because it's abuse of a glitch. There's a cloning glitch in D/P - does abuse of that make you "hardcore"?
In Pokemon's case, it's EVs, IVs, and various move combinations.
Agreed, but...
If everyone has unlimited access to the best moves, then great move combinations in previous games won't be glorified as much because anyone can duplicate that moveset without having to worry about losing the TMs.
Again, many "hardcore" players just hack Pokémon, or use simulators like Shoddy Battle. Those players already aren't affected by the limited nature of TMs, so all this does is put everyone on the same level.
Should I have been permanently barred from obtaining Regirock for having [dukar]ty luck?
No, but only because of the rules you were playing under in your example. I'd argue that if auto-saving after legendary battles was implemented (or, really, even if it wasn't), legendaries in the field would also need to be redesigned such that they couldn't run out of attacks and Struggle themselves to fainting - you'd expect a legendary Pokémon to have legendary amounts of power, not ten or fifteen PP per move.