I too wonder what this seeming collective bad sentiment toward wikipedia is caused by. I think wikipedia perhaps did something that was considered unjust in the past... But I am not aware of what it was.
For a long time, The Wikimedia Foundation was responding to requests to accept Bitcoin donations with:
The Wikimedia Foundation, as a donor-driven organization, has a fiduciary duty to be responsible and prudent with its money. The Foundation does not currently accept Bitcoin or other currencies not backed by the full faith and credit of an issuing government. We do, however, strive to provide as many methods of donating as possible and continue to monitor Bitcoin with interest and may revisit this position should circumstances change.
Of course, this deeply upset a lot of bitcoiners. However, I don't think this is sufficient to explain the level of hate here.