Honestly, I think the reason that you see a lot of people doing the "+1" posts over on THR without adding anything to it is related to the member "ranking" system.
Here on APS, everyone, whether they have posted once or thousands of times is listed as a "Member" on their profile. On THR, the cheap and easy way to get your "Senior Member" status is to go into every other thread and post a quick "+1" with no other comment. Of course the people who see this as their way to respectability fail to see that having "Senior Member" by your name is pretty silly if you haven't been contributing at all to the forum but, for some, that is the way they want to do things.