If you were running rails inside of Torquebox you could make use of the Infinispan Data Grid (http://infinispan.org/) to cache your views. It's underlying linear scalability mechanism is far more mature than Redis Cluster, and it's deployment story is quite nice. You won't get all of the data structures that Redis provides of course, but if all you need is a great cache, and you're already on JRuby then this could be a better fit for your loads.
At the very beginning, Rails made a big deal about aspiring to database agnosticism, and to this day ActiveRecord supports a number of SQL databases out of the box.
The backend for ActiveSupport::Cache::Store is similarly interchangeable (memcached, disk, etc.)
I can see why adding a Redis dependency makes opinionated programmers grumpy, and I predict ActionCable supports other backends than Redis eventually.