He's never called it a bad game AFAIK (as opposed to 8 which he has openly shit on) but if you listen to any of DSP's rambling mini-boomer segments about FF7 (sidenote the man loves the sound of his own fucking voice) you'll notice that he has no actual legitimate criticism for the game itself, all his rants revolve around the hype the game got at the time. He always brings up how it was the first FF game to be on disc, how Square left Nintendo because they were sticking with cartridges, how it released in America on 7th of the 7th 1997, how people only love it because it was their first FF game they played (never mind this same thing could be said about him and his favorite FF game being his first), how stores did a promotional gimmick of giving the first 50 customers a poster/map or some shit, how it was the first FF game to go 3D graphics etc etc.
He even admits he fell for the hype, he fell for the marketing scheme! Then he usually caps his rant off by talking about how at times the game drags and the ending made no sense to him, so the feeling I get is as he was playing FF7 the first time he was fine with it, then he got stuck in the middle of the game somewhere and got pissy, then he eventually finished the game and because he's a massive dipshit didn't understand the culmination of the plot, threw his hands up drunkenly and said "dood this game fucking SUCKS, the ending made no sense dood, anybody who likes this game is just a hypetrain fanboy!" and being the stubborn bacon-brained fuckwit he is never bothered to try and understand the game or why others liked it, instead psychoanalyzed the masses, crowned his own opinion as l33t and moved on with his life pretending to know anything about JRPGs.
https://youtube.com/watch?v=2p1x1m0KZt8
If you watch this compilation you'll notice 99% of what he says is focused on the marketing and consumer reaction side of things. He has always been obsessed with going against consensus, the ultimate contrarian. It's part of why such an immense sped could also give off such a constant air of smugness his whole life. Like with anything there are many things FF7 could be criticized for, nothing is perfect, but Dave doesn't touch on anything that you could really even call a critique of the game itself, just the culture surrounding it.
TL;DR if you say previous FF games are superior in every way and also say FF7 is massively overrated, it drags and the plot makes no sense ("another thing that pissed me auf about da game... the ending, it's horrible!"), you are semantically saying basically the same thing. Not to mention the crossdressing Cloud scene has scarred him mentally for over a decade.
^ This clip is a pretty good example of the semantics, where he clearly dislikes the game but wants to ride the fence too.
Sidenote but I was randomly searching around for FF7 related DSP videos and came across this video of a guy in 2014 doing a FF7 playthrough and he titled it "DSP Strikes Again!" and the joke is he's referring to Don Corneo as DSP. Thought that was some amusing irony considering DSP's rants against that character lmao.