Was it? Why?
Leicester have just won the league with Wes Morgan, Andy King, Robert Huth, Danny Simpson and Marc Albrighton. Southampton finished in the top 6 with Shane Long up front and players like Yoshida, Davis and Fonte key members of the team. All those mentioned are average journeymen, most of them have spent half their careers outside the top flight, and yet they all finished in this year's top 6.
Yes some clubs have signed the odd marquee player, but they always have. West Ham have signed Payet, wow! But they used to have Tevez and Mascherano, and before that Di Canio. And the majority of their squad is still made up of the likes of James Collins, Mark Noble and Aaron Cresswell. Stoke have signed Shaqiri and Bojan, but what have they actually done? They're the sort of names loved by FIFA and Football Manager players, but in reality both their careers have been massively underwhelming. I'd say it was actually a bigger statement when they signed Crouch years ago, when he was still a regular for England.
We shouldn't get Moyes back simply because there are better managers out there, but I see no reason to believe that it's harder to get into the top 6-8 than it used to be. If anything, the huge drop in the quality of the squads of the top teams has made it easier.