I can hear the arguement that D3 should've included more, but it seems to be relative, as I'm happy (bar my gripe with Legendaries) with what I have thus far in the game. Diablo's longevity/complexity largely came with it's expansion.
On your points regarding builds, I agree. If you have to search the net for a build in order to survive/be effective, then something is wrong. I do however feel that this raises a flaw in Blizz's own ideology regarding D3 when it comes to having all builds viable... this however can be fixed.