I think the problem with suicide attempts is it likely is possible for someone to do it during a psychotic episode or, impulsively. Seeing as 'normies' likely will be shocked at the sight of someone trying to commit suicide- seeing as we aren't allowed to discuss it openly- so, they may not have thought about it from all perspectives- they likely will try to stop the person- thinking they are out of their minds.
Companies will restrict selling things like SN because minors may be trying to buy it and a commercial business isn't in a position to assess someone's mental capacity. It shouldn't be their job to either. Plus- why would a company want to be sued by angry parents? A company itself may not be too keen on the idea of people killing themselves with its products either.
I think that's the problem with DIY suicide. Even people who might be more pro-choice probably would still agree that certain things need to be regulated in order to stop children accessing them and impulsive attempts. But, seeing as suicide isn't even legalised in many parts of the world- so, can't be regulated officially via clinics, how else do they do this- other than blanket bans on things they know people use?
I'm not exactly supporting them by the way. I just feel like, as things are at the moment, it's an impossible situation. It's kind of impractical to think reliable suicide methods could become freely available without changes in the law and a whole lot of regulation.
But, like other people have said, they aren't exactly forcing people to live, they are simply making it hard to die. But, not impossible. The police officers let me keep my SN, despite me telling them what I had bought it for. I think the main thing was- I made it clear it wasn't for imminent use and I (hopefully) came across as reasonably mentally stable.
Obviously, anything in public will be stopped if people can stop it. I think, to a certain extent, it's pretty foolish to attempt where there's a strong likelihood you would be noticed and stopped. Plus, I suspect most people don't want them or their children to witness something like that, so they'll prevent it for those reasons also. Some public suicides endanger others too so- same goes.