I personally left Eligius once I learned Luke Jr. used the pool (and thus my hashpower) to execute a 51% attack to destroy an altcoin without my knowledge. I also came across some pretty religiously intolerant posts he made and learned he includes religious text in the blocks Eligius finds which made it easy to switch as well...
Off topic but very interesting. Care to give an example? Kind of relates to KNCMiners as a significant amount of hosted customers were switched to Eligius.