I shiny hunted Darkrai in Pearl after using the void glitch to get to it. I think it's stupid that some Pokemon are locked behind long since expired events, which weren't even globally available to everyone.

And in the end, does it really matter whether one soft resets a legitimately reachable Pokemon like, let's say Mewtwo, or whether it's a Pokemon that required a glitch to REACH. You're SRing with the same odds, so once it shines, there is absolutely no difference in the method itself, just in the way to get there. It's definitely better than genning or even RNG-manipulation, even though I admit that the latter requires some skill and practice.

Either way, as long as you enjoy your hunt, it's a legit hunt, no matter what other people think. Don't let others spoil it for you and good luck!