WINE and some programs require 32-bit software, those of which that do, I don't even use any longer. I have heard you can build a 64-bit WINE but I'm skeptical as to it's usefulness. Anyway, multilib is just something to be careful with from past usage as sometimes it works and sometimes it might not work as well as you want it to.

I think your main issue was wine a windows executable emulation program and not multilib. multilib is just a set of library's dependencies need it by 32bit layer applications for linux as well as wine. I can not see how a set of library's can cause issue for people to be careful with. In the other hand wine might need a specific set of librarys that might not be by default where you need them or even available as the regular multi lib install.... That would make more since as wine is notorious for been some what broken though its gotten a lot better over the years... personally I do not run wine and I have no need for it. I use multilib for android development.

Good Luck to the OP and dont be discourage, multilib env is ok to have just make sure you properly maintain it and update it.