We (as a channel) initially tried to avoid banning Mibbit wholesale, but that strategy failed. I imagine Freenode had similar issues at a larger scale. I can't say that any developers I associate with are unhappy that Mibbit was blocked.

Specifically, on a technical channel:

  <me> Looks like Mibbit was blocked
  <user1> so sick of mibbit luzers
  <user2> nice!
  <user3> mothafuckers who can't be bothered to
  use an IRC client probably don't need to be on IRC
  <user1> had some random moron join #scheme and then
  start /msging me to ask where I was from

It's difficult to find places to engage in community discussions with other high-quality developers without eventually being inundated with low-quality participants. The quoted response may be overtly rude, but the fact is, Mibbit brought exactly the type of users that we're on IRC (and freenode, specifically) to avoid.