Is Twitter just a "big wet kiss?"

So a friend of mind comes over this morning and says Twitter etiquette is starting to annoy him.

Too much of the service gets cluttered up by "big wet kiss" posts, in his opinion. He pointed in particular to people thanking each other for retweeting them. I had to plead guilty to a different Twitter tradition that he might find annoying. I like to tweet a shoutout to people after I see them at a meeting: ("Great seeing so-and-so at xyw today...") I know why I'm doing it -- to build relationships (Who doesn't like a public shoutout?) and because I like seeing such messages myself. Helps me feel in the loop to know who's hanging out together. Still, I always wonder if somebody out there's going, "ok...and I why would I care to know how your stupid meeting went?"

What do you think? Should all the "thank you's" and "good to see ya's" be banished to direct messages only? Or are they a necessary part of Twitter's community-building ecology?