That's roughly the reply from antirez regarding redis being single threaded, just run more processes.
Let's start with Redis being single threaded, the path we are taking is to build "Redis Cluster"...This means that Redis will run 48 instances in a 48 core CPU...
Right, but running redis in that manner is far more operationally-intensive than running several nginx worker threads.
nginx runs workers by default, which (I believe) can be tuned by a couple config options.
To run multiple redis instances as a part of the same cluster, you need a way to shard your data (which you have to reason about client-side), you need separate config files, data directories, etc. for each instance. It's a huge pain.
Let's start with Redis being single threaded, the path we are taking is to build "Redis Cluster"...This means that Redis will run 48 instances in a 48 core CPU...