Sucked again today..

Another crappy ride today. I rode with a group of folks that I don't normally ride with. I joined the ride because it was listed as 15-17 mph. I figured that would easily fit my riding style at this point in the year (middle of winter, holiday pounds still hanging on). I had heard some talk that this group liked to occasionally pick up the pace on some rides, dropping a few people in the process: even though its advertised as a "15-17 mph", no drop ride.
I was able to hang for the first 20 miles and that was it. I knew where I was at that point, so I rode the last 10 miles solo, I took a shorter flatter route back, to finish the 30 miles with a pace of 17.3 mph. I would really like to kwow what the average of the group was at mile 20!
There is another local ride with a faster listed pace at the very same time as this ride. I just can't figure out why these guys don't just go to the faster ride to begin with??? Maybe it makes them feel better to see a dropped rider like myself come straggling in? The beauty of it all is that only 2 guys in the group new I took a different route back, and I ended up hitting the parking lot mid pack with the original riders anyhow. Boneheads!