Is it the reason? I think you don't have right to use Bengali in Meta which is meant for global discussion = English only. It's my personal opinion though.
They shouldn't. Reporting their post should also cause removal of said post.
I guess that's 41 pages.
I think the thread was locked for being a "duplicate" one.
Going through different boards, discussion/service discussion/wallets, you will find the same question being asked repetitvely and such threads ending up getting spammed because such topics are quite easy to spam.
Locking/trashing duplicate threads isn't a stupid reason. Most logical approach to stop spammers from creating repetitive threads with low quality topics.