Whenever someone says G5 either retconned, changed or contradicted anything that happened in G4, I die a little on the inside. Like, yeah; it can be fun to discuss the discrepancies and try to find a workaround, but saying that it ruined G4 is simply ludicrous.
Comments
Well, G4 did the same goddamn thing!
In the episode, we find out that he, along with his Scorpan, his brother, came to the land of Equestria to consume its magic.
Tirek refused, so Scorpan alerted the princesses, Tirek got sent to Tartarus, and Scorpan returned to his homeland.
Well, that may be... however, that's NOT what happened back in G1.
I mean, remember how I said Tirek was a returning villain from a previous generation? That's where he's from.