There is a phenomemon called the "post bubble bustout bonanza", which describe the fact, everyone tries to make it into the money, and because of that many players become rather short. But then after the bubble has burst, there is little value in lasting an orbit or two more, so now players get much more willing to put their stack at risk. Which actually they should.
Moreover in a PKO there is always value in knocking someone out and winning their bounty. So its possible, you saw someone, who was "playing without strategy" or "going all-in a lot with any cards". But it could also be, that they were just playing good poker, and you are the one, who dont understand the correct strategy for this phase of a PKO.
Also its not at all difficult to play in a game with short stacks and loose players. You just go all-in yourself, when its profitable to do so, and then you live with the result. Maybe this is not your idea of "good poker" or "exciting poker", but if you want a lot of postflop play with deep stacks, then you should play cash games. And if you want to avoid some of the "wild
gambling", then play regular MTTs rather than PKOs.