Lately, it seems like there have been many questions tagged for closure that are guilty of little more than ignorance of the subject matter? Despite the fact that they may seem ignorant to those of us in the aviation industry, these questions are not really in violation of site guidelines. For example, when a non-aviator asks a question about the dangers of tabletop runways or the safety margin of 1,000 ft vertical separation, because of something they saw in the news, shouldn’t we be glad that they bring their questions to us? Is this supposed to an experts-and-professionals-only site that turns away amateurs and civilians?
The short answer is most definitely NO - questions should not be closed just for being dumb. There is no such thing as a dumb question as long as (and here's the important part) they are on-topic.
With that said, your specific examples do not make much sense.
The first example you cited entered a queue for "first posts" and received 1 vote that it was off topic and 3 votes for "leave open". The system worked. One person's opinion was overruled by the majority.
The second also entered a first post queue where it was voted to close as opinion based. This resulted in another queue which ended with 3 leave open and 2 close votes. At the moment this question remains open, although it may still be closed as more users vote.
The "system" appears to be working exactly as it should. I see no evidence that either of these questions has been unduly targeted due to being "dumb questions".
Edit: Having determined the motivation of the asker for the 1,000ft question, I cast a vote for opinion-based. They were asking about the motivation of ATC for not separating by more - which nobody except the controller themselves could answer