Totally agree with you.
Personally I'd never go all-in. Investing in something with a bit of a risk (which Crypto definitively is!) you have to realize that you could lose everything you put in at any time. Therefore I'm only ever putting in what I can afford to lose. If I make a profit it's nice.
If I lose everything I'll just not be able to afford something nice I could've bought instead... but there won't be any vital harm!