Wouldn't meeting only with people that one likes lead to reinforcing one's echo chamber?
It's that echo chamber of "you can do it" that often leads to people actually doing it.
But I can see how a positive echo chamber could help get something off the ground.
Besides, in a work context it's more likely to be people who want your time and effort for something that's not in your goals. Or simply bores. I used to work somewhere with a negative productivity manager: not only did he not do anything useful, he had a tendency to stand next to you and tell dull long stories of How It Was In The Old Days.