Saying hello is not sucking up. Neither are explaining dungeon mechanics, congratulating other players on their level ups or achievements or being patient with people who make mistakes. Those things are just part of the way people should always act towards each other - a.k.a. civility.

Performing your role well is just one of the factors that can lead to getting a recommendation. I haven't changed my way of playing or treating others since 2.1, but I have noticed a marked improvement in the attitudes of people in the DF. And it's all for the better.

Except when someone begs for a recommendation before the dungeon/heist has even begun. That's just cheap.