As someone who only play DPS, and almost only played MNK for a long time now, I mostly only get a couple of random commendations every now and then...

There are times when I get 2-3 commendations (dungeons) on a run, but I can tell that they had used a parser those runs. That's the problem with DPS (not a huge problem though), Tank and healers are pretty easy to determine if they have done a good job, but unless you use a parser, it isn't all that easy to determine how good a DPS is doing.