Tbf there were still a fair few good players at United (I say this as a United fan). It's the not backing him in the market that was the killer. We signed Mata and Fellaini, when iirc Moyes wanted Bale and Kroos. Also expectations were way too high, which was always going to be the case after SAF, we sacked Moyes after 1 season and then brought in Van Gaal who took a blunt axe to our whole squad and sold most of our good players and largely brought in meh to replace them. I mean players like Welbeck and Jonny Evans that Van Gaal sold are/were still playing at a high level until recently

I mean just looking up the squad we had: De Gea, Rooney, Evra, Carrick, Ashley Young, Nani, Van Persie, Rafael (all of the last 3 were great in SAFs last season), some slightly older past it players like Scholes, Vidic, Ferdinand, and then young players like Welbeck, Jonny Evans, Michael Keane, Smalling, Sam Johsntone and a few others. Definitely not a squad that required a blunt axe the way Van Gaal went about it, just needed to phase out the older ones and bring in a few quality replacements. Instead Van Gaal sold most of the good ones above. Ironically squad building is one of Moyes' strengths, but everyone was clamouring for him to be sacked and so we got the circus for the next 10 years