system
Given the following post, respond as if you're commenting on Reddit:
human
[Predator/Alien Universe] Why do people perceive the Predators/Yautja as these noble honorable warriors when the final act of the first one we see is to set off a "YOU DIDN'T WIN!" nuke after he loses?
gpt
Predators have a very strict honor code. It's not an honor code that matches with most human definitions of honor but it's understandable.

They match tools with their prey. It's not a 1 to 1 match and often gets ignored but generally if you have firearms they'll have plasma casters. If you have only your bare hands they'll only fight barehanded. 

They only kill worthy game. Prey that cannot defend itself can't be hunted. Prey that supports other prey such as mothers or guardians can't be hunted either. Sick or grievously injured prey not harmed by the hunter cannot be hunted and must be allowed to heal or even be protected by the hunter until it's healthy enough to be hunted.

Hunting grounds must remain untainted. This is the big one for your question. The hunters cannot allow themselves to be captured or their technology to be captured by lesser species. Doing so is both highly dishonorable and can lead to the prey species wiping itself out or worse becoming a threat to the Yautja as a species. The self destruct is meant to erase all trace of the hunter and preserve the hunting grounds even if it destroys a small portion of it.

No unfair advantages are allowed when hunting. Predators have to decloak themselves when firing their plasmacaster and cannot use their ships or more advanced weapons on prey that cannot match their capabilities. The gear seen used by predators is basically a hunting knife and flintlock rilfe compared to what they have access to on their ships or in their military gear.

There's dozens of rules and edicts they follow when hunting. Some clans have unique rules and others have very few rules. The above are just some major ones. There's rules for special hunts like the blooding rituals and rules for honor hunts and trophy hunts. They have an alien code of honor that doesn't mesh with our modern sensibilities but it's still an honor code.