I sort of agree with you, in that if I was going to start a company I would totally Just Use Rails.
But I think that's just where Rails is in its lifecycle. We all learned a lot from it, and we've started to build alternatives, but nothing has really coalesced yet.
Flash forward 5 years and there will be post-Rails frameworks that have worked their kinks out and are starting to enjoy the network effects that Rails has. At that point Rails will lose a lot of its advantage.
But I think that's just where Rails is in its lifecycle. We all learned a lot from it, and we've started to build alternatives, but nothing has really coalesced yet.
Flash forward 5 years and there will be post-Rails frameworks that have worked their kinks out and are starting to enjoy the network effects that Rails has. At that point Rails will lose a lot of its advantage.