Actually, I really like it when people acknowledge any vents [good or bad] that I post because it feels like the person is saying "hey, I care" even if they don't leave a comment, as I usually disable them after a day or two anyway.
However, I know a handful of people who get really upset and even pissed when people acknowledge vents via favoriting [or reblogging, in the case of Tumblr since this kind of stuff happens a lot over there] and I don't get it. If you don't want people to favorite or reblog or retweet something, then don't post it. Not wanting comments is understandable, that's why things like being able to disable comments are available. At the end of the day, it's the internet, and you can't place something on public domain and expect it not to get acknowledged.
Personally, I don't give people shit about it... but thanks to Tumblr, it has successfully become one of my pet peeves.