I don't believe thanks is necessary. You said this is the only forum where thanks is not given. I totally disagree. I have been a member/moderator in many tech forums. It is like that all over. In fact, some forums do not allow it because it could fill up email accounts when getting email notifications.
I have one main rule when helping. if I ask a question for more information, clarification or give suggestions that are challenge or dont get replies, I will no longer help.
as far as questions being posed over and over again. yes it does get tiring but you must remember they are from individuals who are trying to solve an issue by joining a strange forum while frustrated, upset, and lost. they are are not going to spend time trying to find the rules, do a search and other things those of us who has been using forums for years already know. besides, over the years, I have found most forum searches are worthless and a waste of time. one other thing, if you are going to ask for help, it is best to ask first since it does take time to get answers. while they are waiting, who said they quit searching. by the time they finished searching maybe an answer will be ready. why spend time searching then ask when you can ask then search.
as far as why a lot of questions go unanswered, nobody lives here, there are only a couple here that helps regularly so questions get missed. it is also to the point where alexa is changing so fast that what was good answer before are not good answers anymore. I doubt there are any experts here. those who help know what they know through their own experiences and a little search now and then to help.
lately some of the questions seemed to be a bit too technical for most - and this includes me. skills and ifttt are constantly changing, new commands are constantly being added, new technology from 3rd parties that work with alexa are coming on the market so it is difficult to give a definite yes or no on most things anymore. I ran across a question today where a week ago it could be done but not anymore. then there are all the different countries where the features are different.