I think given that LVG has struggled too, that the job was never going to be easy.
That said, one of his flaws, which us, as Evertonians noticed, and criticised, was his approach to so many games, he'd play negatively, and we'd be found out, Norwich's, West Brom's would get results from us being over cautious, for every well ground out performance, there was a frustrating performance, without trying to down us a club too much, Everton don't quite bring the same scare factor as United do, well under the Fergie reign, a good team, you bet, but when a team sees a weakness, somewhat David Vs. Goliath-esque, they can swoop, and when Moyes openly admits to trying to play the way he was 'so successful with' for us, with United, then the WBA's, Southampton's etc.. lose their fear and they're going to get a result.
A not very nice man by all accounts, and for me, not a very successful one, obviously the way he left United was harsh, but i don't feel for him, i mean 10 months into a 5-years, 100,000k a week contract, which got paid off, well yeah, there you go, that's a cool £10m+ for being 'successful', 14-years a manager, zero trophies. To put that in perspective, Martinez, Laudraup, McLeish, Redknapp, Ramos, McClaren and Souness all had more success in terms of silverware, in the time that Moyes was head coach of Everton. You're not remembered for finishing in the top half of the table for 80% of your career, but you are for Silverware.