You have to realize that it's still early season and most of the boaters on here don't have enough whitewater to distract them from talking shit on the internet quite yet. The good news is our runoff looks like it's going to come early this year, so they'll be preoccupied within a month until sometime in August.
So, if you're someone with a few trips under your belt and just haven't taken the steps to buy a boat / learn to row a boat / date someone with a boat who knows how to row it, then these guys are right and you should know better.
However, if you are new to boating and someone suggested Mountain Buzz as a great place to get into the sport, then welcome. I was in your shoes a while ago and met a great group of friends on here that I still boat with today. My advice - instead of trying freeload on someone else's trip straight off the bat, which rarely turns out pleasant for either party, why not instead ask if there are any boaters near where you live? Buy them a beer, let them see that you're actually a pretty cool guy (which you may not be), and then you'll be more likely to be invited on a trip. Show them that you are willing to work hard, help with the shuttle, don't fuck with anyone's straps on their boat, and you'll probably be welcome back on another trip.
Or troll the bars in Moab. You never know what'll turn up.
“May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view. May your mountains rise into and above the clouds.”-Ed Abbey