[malyk]

memory overhead (both for the machine and human), modifying core classes unnecessarily, complexity of third party software, setting defaults to on that aren't applicable to 90% of apps (see turbolinks which breaks the way the web and browsers work).

I'll admit to being on a hard-core minimalist, simplicity, explicit coding kick recently, so I'm already biased against behemoth frameworks. Rails is wonderful if you need that level of complexity/features. I don't think most apps do and we're "forcing" everyone to write basecamp when that is overengineering for most apps.

[vectorpush]

I'd add security to that list. Rails' most notorious vulnerability was the result of an on-by-default feature that 90% of developers never even needed. I'm not suggesting that Rails is inherently insecure or that Sinatra/Rack cannot be exploited, but less unnecessary code leaves less potential for vulnerabilities; this is especially true in the Ruby world where many developers are eager to `gem install` anything with a few stars on github.