Distrust of your peers won't bring down bitcoin but it sure won't help it get anywhere. By that I mean more focus should be on how to sustain bitcoin in the long run. Dying GPU mining means fewer miners with ASICs becoming more common so more future bitcoins for fewer people. Fewer coins being mined to cover costs. Transactions per block growing too quickly for current 1MB size limit (increased size will hurt smaller pools but most people don't give a shit). Lost coins (a significant amount of the 11.3m -ish coins currently). We get fair discussion on these items but they are overshadowed by flaming competitions among the large drama user base over future predictions to the point that it's not worth discussing any new insight. To quote a work saying I know, negativity kills productivity.

I think this is the biggest challenge of bitcoin though I'm hopeful that with an increasing difficulty will be good for the community. Less complaining originating from miners looking to make any money at all and more on uses for bitcoin and solving problems like the sliver above. I don't think bitcoins should really be viewed as a way to make money at all and I only support covering transaction costs in the long run (no problem with speculation though for making/losing money).