Price is only part of why I preferred the S&W over the other guns I looked at. If I wanted a reliable, accurate but less inexpensive .22 rifle I would have bought a basic 10/22!
While there are many people who like their guns made of only metal and wood (I do myself in most cases), I think a polymer frame/stock is a good choice for an all purpose gun, especially a .22. It's lighter (weight is good for recoil control but a .22 has no recoil), won't rust, is much less likely to break or warp, is usually cheaper to make and can be molded into almost any shape. Some folks have suggested I should have got the basic 10/22 and "tricked" it out and I considered it. However, between the cost of a new gun, an aftermarket stock and other parts that met my requirements, it would have cost as much as the S&W by the time I'd purchased everything separately, quite possibly more.
As Windwalker said, everyone has their own opinion. For me the 15-22 best filled the requirements I was looking for in a .22 rifle at a price I was willing to pay. For someone else it could be a Colt, Ruger "AR", SIG or any number of rifles that are becoming available to shooters who want something other than the bolt action, single shot or more "traditional" styled semi-auto's that have been around for decades.