It's an interesting thought.

I'm primarily a Ruby developer. Literally every single time I've started a web-oriented project using something like Sinatra or Padrino etc., I've ended up regretting it. I end up building a shitty, half-featured, buggy version of Rails. My experience is that most other projects end up the same.

I suppose mileage may vary; perhaps it's easier to write bloated apps in Rails. I'm not convinced that's a good reason to avoid it, though.