I notice sometimes that the person who gets the MHO says ‘thank you’ but shouldn’t the question asker be thankful for receiving a helpful opinion? Is it necessary for the opinion owner to say ‘thank you’?
Yeah I see what you mean but at the same time a lot of opinions could be helpful so you're lucky that he/she picked yours over someone else's.
Also there's the fact that not all of the questions on this site are asking for advice some are fun and random and just like to here our personal opinion so it's more so a random selection or who said what the QA wanted to here.
It depends on the question. If my question is trivial, like, how many shoes do you own? Then I won't say I'm thankful for the answer. But if I really needed advice or got a great answer regarding a deep question, then I'm extremely thankful. If anyone gives me mho, I'm sure to thank them.