No.Utilization is fine but application utilizing platform should not invalidate platform's one of the main reason it was supported by many!

What you are saying is acceptable if users are allowed use those developed apps freely(without app.net membership)but here first we need membership to access these apps!

Then don't use the applications which use ads. App.net itself is still free of ads - you cannot say the same of Twitter.

This is akin to saying that Windows 8 is filled with advertisements because the Music and Video apps link to the appropriate store frontends.