Well, it is bad that it is not planned. What should we do to make it to be planned ? Create some poll, gather some votes, what ?
I really doubt there will ever be a Mikrotik-developed EoIP client for windows. But if you check github you'll see there are several projects which have successfully implemented Mikrotik-compatible EoIP on Linux, OpenWrt, etc... So a windows client would just need to be self-developed in a similar way. Nobody's done it yet probably because it's easier just to spin up a VM with chr, buy a mikrotik, or an openwrt-compatible router. I agree it could be a useful tool though, hopefully someone develops it