If you choose a platform that needs tools, if you give up the viral soft collaboration of View Source and copy-and-paste mashups and being able to jam jQuery in the hole that used to have Prototype in it, you lose what gave the web its distributed evolution and incrementalism. You lose what made the web great, and what made the web win. If someone tells you that their platform is the web, only better, there is a very easy test that you can use:
I took the liberty of highlighting the Web 2.0ish language.
Both of those are great reads, I highly recommend taking a few minutes to read them.