Does Ruby on Rails affect how a web page looks?
Ruby on Rails is a server side technology, so it doesn't lend any specific quality to the user visible design. That said, it is a "trendy" technology so people who are likely to write their back-end code with RoR are likely to choose a particular "Web 2.0" style for their views.
As a Ruby on Rails developer, I can tell you that most Ruby on Rails developers are passionate about their work and we pay a lot of attention to details when building websites as much backend as front end. Its not just a trend, its a way of thinking and working.