I have a short temper but have learned to control it around people, however, online I get very angry at all the stupid players who are just gamblers (no skill involved) and lose so much with the best hand until the river.
Well, get used to it. This may sound cliche, but this is poker. As long as its within the rules and not cheating in any way, people can play how they want.
With that said, theres nothing stopping someone from playing like a maniac and getting 'lucky' all the time. Nor is there anything stopping someone from wanting to gamble with their chips. Players will not play how you want them to play/how you think they should play nor do they have to play within your skill level.
That sooner you realize that, the sooner you learn how to adjust your play vs different opponents.
Also, please don't think you're supposed to win hands just because it's the best or better than your opponents. As long as their are still cards to be seen and villain has outs [they're not drawing 100% dead] your hand is susceptible to losing.