I think the most frequent complaint of mine is unprofessionalism on the end of the company in getting back to the candidates. It's pretty much being an asshole to not get back to the candidate who takes the time to come and interview with them. I understand that they may have many a people applying for positions and this and that but there are some common courtesies. And I'm not even talking about a hyper competitive job where hundreds apply for a few positions. This has happened when I was one of the 2 people considered for the position and what not. This one time I got an email from HR after a couple of months of interviewing asking me if I was still interested in the position etc.
Completely agree - take the time, even if it's a standard no thank you email, to get back to the candidate. There are plenty of companies that do this, and while I can take the rejection without any hard feelings if that is the outcome, I will lose respect for the company when no response is given.
Unfortunately, I think that this is all too common, especially in other (non-software) fields. There's almost no excuse for it (short of "the company went bankrupt the day of the interview and all hands were laid off")
