Currently, we only supply ruby-plus-devkit for Windows clients that want to utilize Ruby in their habitat or effortless builds. This package is huge, and when updating it can take down networks and on-prem builders with the amount of traffic it generates at scale.
There are clients who would like to use ruby without the dev kit in their on-prem package builds. There would also be advantage to releasing chef/chef-infra-client without a dependency on devkit. The reason given for using devkit was that it's needed if customers need to build gems. They can't currently build gems on Windows systems in traditional chef-client, so why are we forcing a huge package on them for effortless? They could easily build their own chef-infra-client package if it turns out they do need that gem compiling capability.