Well, not quite never. Steve Fry of the Topeka Capital-Journal has this story on the lawyer in the Kansas case of Phillip Cheatham.
Should we see more such proceedings? Bear in mind that it is now considered mandatory in capital appellate defense culture to savagely attack the trial lawyer regardless of how good a job he actually did. When was the last time you saw an initial collateral review petition in a capital case that did not allege ineffective assistance? I can't think of any offhand. And of course for a judge or panel itching to find an excuse to overturn the sentence, IAC makes a juicy target. The claims are so "fact bound" that a grant of relief is less likely to be reversed on discretionary review further up the chain.
If bar discipline proceedings regularly follow IAC reversals, and if such reversals are frequently made even if the lawyer did, in fact, do a good job, then lawyers may shun capital cases at trial.
On the other hand, if bar discipline proceedings are common, lawyers would have a stronger incentive not to fall on their swords in the collateral review proceeding. They would have an incentive to do what civil lawyers do to protect themselves from accusations of malpractice. They would document as they go along to protect themselves from potential claims and come out with guns blazing when wrongly accused.