It's not that easy, I've had mixed experiences with bug reporting, from bugs being fixed almost immediately or in a day or two after I reported it on the developers mailing list, to being a mostly ignored bugzilla ticket that will be eventually purged (firefox). It's always easier when a clear test case can be presented, such as a minimal script that reproduces the problem. However not all bugs can be that easily reproduced.
Of course it's still easier and more effective to report bugs of open source programs that closed source. It's hard to even bother reporting closed source programs bugs, you won't even get past the first line tech support...