Sharding is pretty much a necessary evil with the SHEER volume of players coming back for launch days now. Back in Vanilla's first day it was just over 100k players playing together but now it is millions and it's just not feasible for the servers as we saw during the Warlords of Draenor launch, where they gave us free game time because of the queues and massive server problems causing many people not to be able to play at all the entire launch weekend.
Without sharding, there will probably be hours of queues again with servers going down which will put us all back in queues again. You might not be able to play with your friends anyway depending on queue positions. I'd rather be able to play and not see EVERY single person than spending hours on log in screens being frustrated.
I totally understand people not wanting it and I do think that if it affects your experience that much that it is the best course of action to just start your journey when they remove it. We have waited so long for official Classic another week or two won't hurt.
But didn't that happen with BFA launch ?
Sharding didn't save you.
The login servers aren't a part of sharding.