You can use 150x and make profit too, if you can of course, the amount you are leveraging is not the problem here, you can use any type of amount and make any kind of profit, that is never the point. I think it is quite important to remember that we are going to lose a lot more quicker if we are wrong, that is the point of it.
I hope that it could get to a level where we could make some good return from it and 150x or 2x we both all win, but when the price is going the opposite direction, I rather be at 2x than be at 150x, that would make sense. I mean margin-wise, you can cover 2x very easily, whereas you can't really make that 150x at all. So, yeah there are people with 10x who make profit, but there are also many who doesn't.
The problem is that people who do 10x have very little chance to stay, but also more than 150x people as well. In an example, if you have 10 thousand dollars, and you want to do 10x, that means you will be acted as if you invested 100k, so by logic if it goes to 90k, you are gone, that means 10% drop makes you lose it all, but at 100x for example, that 10k will become 1 million, and you will lose it all at 990k, so even 1% would make you lose it all. That's the difference and this is why 10x sounds better.
Obviously at 2x, you would need to lose 50% to lose it all, hence it's much better but 10% feels alright risk for some people. At worst case, they think they can get out before they can lose it all, or top the margin a bit more to lower the risk.