This user is no longer active on Wikipedia as of March 2013.
In the many years I edited at Wikipedia, I tolerated:
Bullies.
Cliques.
Editors with sociopathic personalities.
Editors who crave power (often with little content-building desire or activity).
Editors with no desire to learn, let alone respect, policy and guidelines.
Editors who dominate others via a too-strict adherence to policy and guidelines.
Wikipedia's inability to define, let alone apply "consensus".
Wikipedia's unusual and inconsistent definition of "notable".
The mysteries of Wikipedia's hierarchy (including communications not transparent to the community).
The admin job-for-life culture.
Spending most of the first hour of my day fighting vandalism.
Software development not completely specified by the developers' customers: the editing community.
Editors who believe that the aesthetic appeal of articles is more important than their content.
Luddite editors who fight to the death to resist progressing Wikipedia from being a nineteenth-century textbook (especially when it comes to referencing).
The degradation of article content mainly due to the poorly-worded additions of the uninformed.
Inconsistencies across articles which are largely due to the bizarre "first major contributor wins" philosophy.
The exodus of good editors.
I woke this morning with the certainty that I no longer want to tolerate these, and I can't envisage a reversal in Wikipedia's failure to deal with such issues.
Thank you to the editors whom I respect and with whom I've enjoyed working (you know who you are, so I wont risk omission via enumeration). Best wishes to you all, and I hope that you can continue the good work with strength which I no longer posses. In quiet moments there was joy in building content, however I now realise that it is only a matter of time before one or more of the above points further destroys that joy.