This makes ongoing maintenance difficult, as it requires that RSpec Rails' maintainers be conscious of every Rails version that might be loaded.

Our need is therefore best characterised by cost of maintenance. Having to maintain several versions of Rails and Ruby costs us a lot. It makes our development slower, and forces us to write against Rails versions that most people no longer use.

It also aims to support only modern browsers to keep things simple.

Not only do changes need to be tested against Ice Cream Sandwich's codebase, it is also often necessary to use workarounds due to API restrictions.