[sanderjd]

There are a few ways to answer the (definitely relevant) question of "if you're doing things this way, what does rails give you?" In some cases, the answer is "nothing", and people really just want sinatra if they really like ruby, or one of the many lighter-weight libraries that other languages have. In some cases, the answer is "actionpack is still really good at what it does, even if it's just used as an HTTP adapter". In some cases, the answer is "activerecord is a really nice ORM". Etc. But I think in most cases, it's because there are just lots of libraries written for rails, and using sinatra or padrino (last I looked) tends to result in re-writing some things that you would otherwise get for free. Although sometimes in order to use those libraries you need to be doing things "the rails way" anyway.