I'll also have to invoke a second, and less ambiguous saying: "Learn from the mistakes of others, you won't live long enough to make them all yourself.".
Having spent a lot of my life repairing and maintaining airplanes, I know what goes into making one fly - it's a lot of work! I cringe thinking about thousands of hours of people's caring effort simply wasted when someone wrecks a plane attempting something silly - but yes, we do have to give some room for pilots to develop the judgement to become wise. That said, they may risk their life doing so, but not others - innocent people are not a part of a pilot's judgement building. So dropping your gliding airplane into a built up area because of the pilot's poor judgement is not on = rule. Pilots taking off, and flying super steep, unsafe Vx (or slower) climbs for no good reason other than some silly misinterpretation of what "STOL" means in the civil world - only risks the pilot (notice that these pilot's don't carry pax - too heavy!) and the thousands of hours of airplane building labour (maybe theirs), so guidance, but no rule against.
In my early days, I was a part of a team which recovered wrecked airplanes. Often we'd fly into the remote wreck site in floatplanes. I was always thinking about what may have caused that accident, so whatever that was, I did not do it! In middle days, I would train pilots, I would give them my best as to why to do, or not do things based upon my experience - both good and bad. In my middle to latter days, during training, I took my eyes off my student at the wrong time, and allowed my student to put us both in hospital for three months. In my latter days, I approve modifications to airplanes (I have for 25 years, I don't train anymore). So, I think about the flight manual supplement I'm going to prepare for the modified airplane. Sometimes it will present a procedure (a best way to do this), sometimes with an amplified procedure (explaining why). Sometimes an "avoid" to say you can do it, but better if you don't, and if I'm certain, a prohibition - you don't get to even attempt this legally. What you do after that is up to you.
I don't have the authority to regulate who flies where nor how high (except over my own home runway - I don't like my house getting buzzed). I leave that the authorities, but it's for a reason which I understand and agree with.
Another saying, "If you think safety is expensive, try an accident!".