Any of the top 4 teams in England could legitimately win the CL on a good day. Liverpool and Arsenal, two historically powerful clubs are not even in the top 4 the competition for a CL spot in the PL is enough of an indicator of the league's quality IMO. That clubs like Chelsea, who have a starting XI every bit as good as Bayern or even Real (Torres aside) can have such huge fluctuations in form speaks more to the pressure that the top English clubs face, not inferiority. City, United, Arsenal, Chelsea all start their seasons with the intention of winning the title. Only two teams do that in Germany, Spain and maybe three in Italy.
Anyway this is my take
The reason Arsenal and Liverpool aren't in the top 4 is because their squads aren't at that level anymore. Though obviously all the big clubs are rebuilding their squads (besides Arsenal....) so the PL will have a resurgence. Every other league in Europe won't be able to cope with the huge new TV deal, that's for sure.
Plus, you can't honestly say with a straight face that Arsenal start their season with the intention of winning the title. But I agree with your point for the most part.