I've had the same question, myself. Arts & Crafts is still in Beta, and the posting volume is surprisingly low, especially for a pleasant site with subject matter that should have wide interest. We average probably on the order of one question a day, which I'm not sure is enough for a viable site. So there is probably some sensitivity about not being overly aggressive closing questions.
That gets compounded when a question goes HNQ (Hot Network Question). That drives a lot of viewers to the site, which can be good to build the user base. Unless a question is really bad, nobody wants to shut it down while it's attracting views. Two of your examples are in that category: Planes of the head and How should I clean these beach beds?.
On the first, maybe other people also just don't get it. The question received two helpful answers. I'm OK with that one in a generic sense, but it isn't my subject area.
The second probably should be closed now that it's no longer HNQ. I commented on it that it didn't seem on topic. But there is often a broader perspective where something might be. I gave an example for migrating it to the Home Improvement site, where lawn furniture isn't on topic but the same question applies to cleaning vinyl siding, which is, so the information is relevant to the site. I contemplated here that crafters could make something from plastic that lives outside and would similarly need cleaning, or they might upcycle some old plastic stuff covered with lichen and would need to clean it first. So it was within the realm of possibility that it could be on-topic if framed appropriately. Any thoughts on whether the question should be reframed or closed?
This site is one of the friendliest in the network. It's a stark contrast with many of the big sites, where the atmosphere is often downright rude. The active user base here is extremely supportive; people are here to help others and have fun. We often bend over backwards to improve poor questions so they can remain open, and we have a general high tolerance for questions that need work. Maybe too high a tolerance. The idea of putting a question on hold is to suspend activity on it while it's turned into a good question. No matter how you word it, though, it isn't the experience the poster expected when they came here. I've seen questions closed in the nicest way here, but we may be "too supportive" in not closing questions that should be.
Letting in a lot of low quality questions will degrade the site in the long run because good content gets diluted by noise. We probably do need to shift the balance a little, and be more willing to close questions that need it (while being nice about it).
That said, this site has a scope that can make that difficult. Arts & Crafts covers a huge territory. Most users have expertise in a few of the topics, but few users have more than a passing acquaintance with many other topics in the site's scope. Questions can seem overly broad or unclear (or even off-topic), to someone who isn't intimately familiar with the topic, but make perfect sense to someone who is.
I run into that a lot here. I don't have an art background, so many of the art questions seem to be low quality or unclear in one way or another. Then the question receives an answer or two, and the answers provide perspective in which the question makes sense. So I rarely VTC questions whose subject matter I'm not familiar with. OTOH, I was the first to VTC How to deal with artist's block?. Then Marian's answer demonstrated that the question was answerable, and it seems to be widely applicable. I gave it the benefit of the doubt and voted to reopen.
DVD/Bluray Plastic Cover was clear to me when I answered, only I was thinking of cases other than the style the OP had in mind. That didn't become obvious until the OP commented. I discovered that there is a case style in which the comment makes sense and have asked the OP to confirm. If they get back quickly, we can clarify the question and I'll adjust the answer. Since we likely now know what the OP is talking about, I'm tempted to give them a chance to clarify before closing the question. But if they don't get back, I agree that the question is a problem as-is.
I'm OK with the CriCut question. More information will help people answer, but I suspect people familiar with CriCut will be familiar with the problem. The problem I see is that our user base has little familiarity with CriCut. Something can be theoretically on-topic, but if we have no expertise here to answer it, those questions will either remain unanswered or attract guesses from well-meaning readers. Neither is desirable. The best solution might be to clarify the site scope and move the on-topic boundary, since that one falls in the gray area, anyway.
All that said, we seem to have attracted an unusually high number of questionable posts in the last month or two. The issue may be more that we're seeing a lot of them than that our standards have a problem (although when the main page is full of [Closed] questions, users may be more hesitant to close even more. We've had several HNQ questions, which is unusual, and people have been stuck at home due to the corona virus, so maybe more are trying crafting. Those kinds of things could account for a recent rise in visitors with little formal training, and questions of lower quality.
So bottom line? I recognize what you're describing and have had similar thoughts myself. It's a definite maybe.