Tim Bray's rationale for advocating PHP and Ruby on Rails:
If you and I have the same good idea for a community-based Web site on the same day, and mine is on the air in five months and yours in eight, then you’re dead. And it doesn’t matter if yours is better, because the community has gathered.
Twitter would be the canonical example. They went with Rails because it let them build fast; and they built fast...they’re in a very good place. Smart people tell me that Pownce and Jaiku are slicker and better but who cares?
There are a few problems with this line of reasoning. First, five months to build a Web app with Rails is pathetic. Second, Yahoo was first to market, and Google won. Third, Twitter is not profitable, and if it went out of business today, its entire community could migrate to a new system overnight.
The Rails community does not need people who evangelize to the venture capital culture that using Rails makes your startup a faster, nimbler locust. With a few exceptions the venture capital culture is fundmentally unhealthy. Many things that the VC culture has given the world in the last decade, both in terms of technologies and economic trends, have been bad for everybody involved.
Similarly, putting Rails in a category with PHP is not good for Rails. Rails already has too many things in common with PHP, both technologically and culturally. This is a bad thing.
Long story short, Tim Bray shows up on my radar way too often.