1. Escape from the crowd
Going boating means getting away from people you haven't chosen to have near you. Smaller boats like center consoles might be so popular because they limit the number of folks who can tag along. "Sorry, Aunt Harriet, we only have enough lifejackets for four. See you when we get back!"
2. Enjoy nature
Along most shorelines, there's a way to escape by boat and enjoy a quiet cove, surrounded by nothing but empty shoreline and bird calls. Whether you get away for an hour or a week, it will improve your outlook on shore life.
3. Hang with friends
What's better than a Sunday spent rafted up with buddies? Swimming, paddling, towing, beaching... it's all about spending time with friends who also enjoy being on the water.
4. Spend time with your kids
At certain ages growing up (basically, from 12 to 25), parents are to be avoided at all costs. But on the water, they become captain and first mate: they're still in charge, but it's easier for everyone to understand the rules. Treating your kids as a member of the crew, rather than as kids, will make it easier to spend time together—even in the small confines of your average boat.
5. Act like a pirate
We're never too old to pretend to be pirates when on the water. "Talk like a pirate" day might only come around once a year (arggh), but any given afternoon could be the right time to board (read, raft up with) another boat for a mock battle, or at least a friendly chat.
That's my list. I'm sure there are more... did I miss anything that should be included here?