I lost 60lbs last year on my own with the oldest form of Weight Watcher's points I've ever encountered. It just took more dedication on my part because:
I didn't have that "I'm paying for this, I'm going to get the most of out it" mentality I have now
In addition, it became really easy for me to start regaining weight because if I didn't want to get on the scale, I just didn't.
So, while I think its totally possible to do it at home, you just have to make sure you're holding yourself accountable