You do not have to convince me of the novel merits of multiboxing. I recently helped my gf start playing this game, and we saw a multiboxer and I explained what we were seeing. During that explanation I said something a la, “I have never done it, but I can totally understand the appeal in the meta-game of it”
I’m just saying, overall, it is what it is. The (typical) portion of the community that will ‘discuss’ this with you will probably be a vocal and confused minority who would rather find a roundabout way of gloating about the changes to the game than to engage in any kind of constructive or whimsical reminiscence with you.
If you can find a way to ‘reset’ your expectations (I myself have struggled with this in analogous situations/changes to the game and other places in life), you might be able to re-learn how to enjoy it in another way. For instance with the content you feel you missed out on… maybe you can find new ways to have fun.
Anecdotally, my recent ‘change my expectations’ has led me to exploring, and having a pretty good time with, pet battling! I am not into Pokemon, etc., and only ever pet battled in the past to get rep/flying (Broken Shore). Now, suddenly, I have turned a page, and now I am getting to experience and enjoy this content!
There’s a lot of game and fun to be had outside multiboxing, or any-given-activity-you-have-personally-grown-to-love-the-most-and-blizz-changes. “I’m going to unsub!” it the typical, tragic response.
Don’t cut your nose to spite your face, and don’t drink poison expecting it to hurt the other person =)