The jungler is far from completely safe. The jungler puts his neck on the line to provide you with:
Frequent and unpredictable ganks (which, if they are unsuccessful, he will be blamed for regardless of whose fault it was
Two extra lane's worth of exp and gold (the second solo lane's, and his own) in most situations (that is, if he isn't heavily counterjungled, he isn't ganked, his teammates don't overextend like idiots and die for it, his teammates call MIAs so he doesn't get jumped, etc.)
A lane that will be nearly impossible for the enemy not to overextend in (if you have a Denyplank in their 2, you're boned though)
Extra control over dragon (190 gold to 5 champions = 950 = 3 champion kills of gold = YES PLEASE)
A jungler is always in danger because the major threats to him are as unpredictable as he is to the enemy.
He risks being jumped by an enemy jungler at higher health, having his buffs stolen and getting his jungle run gimped, being ganked, having his own gank attempts interrupted by enemy junglers or roaming gankers, being blamed for his team's failures, and being assumed to be unimportant by people like you.
Watch these:
http://www.youtube.com/watch?v=n7DfqdJ_HVohttp://www.youtube.com/watch?v=HEtWVVmcNOcThen decide whether or not to continue complaining.
Also, if you're not good enough to manage a 1v2 or you're a poor champion for it (e.g. Garen, Singed, people who can't stop their tower from being pushed, people who can't last hit while doing so, etc.) then you have no business being there.