Broke players are because of poker or external factors

[rimanosov]

I've been playing for seven months online, and I'm still learning (that's good to recognize)
I have a question regarding the poker broked.

When successful poker players go broke, it usually has to do with his poker game, for example long bad streak, bad luck. Or factors different from poker, expending too much...

What I want to know is. When poker players go broke is because of poker (luck always beat skill in the long run), or because external factors (skill always beat luck in the long run, but some successful player do stupid things that kill the success)?