I am a big fan of the .22 WMR. It is has a far cry more power than a .22 lr.
I was removing some large rodents from a ranch last year and my .17 was not exiting. It was not even stopping the things on a couple occassions because the bullet comes apart so fast you dont get any penetration on a heavier animal. But from the .22 wmr, out to just under 300meters, it stopped them where they stood. I dont think I need to make the graphic reference to the end result. At any given range, the .22 WMR is more effective on larger animals than a .17.
As another poster mentioned, the .22 wmr has another advantage over the .17. You dont have to calculate for the slightest of breezes with the heavier bullet. A .17 hmr drifts a lot. Even the slightest of winds require compensation. The best part about this is that the .22 WMR drifts about as much as a .22 lr, which most people have a lot of experience with. This gives a feel for your correction in a given wind much more intuitively than with the .17.
Now dont get me wrong. I have shot cases of .17 ammo on gopher patches to great effect. I was able to learn to compensate for wind with it. It just took a bit. And its a really flat shooting cartridge so you dont spend much time thinking about bullet drop. Its a great caliber for little pests. Its a very specialized cartridge.
I dont find .22 wmr expensive when you look at what it does. For my purposes its almost as good as a .223, at less than half the price, and I dont have to spend a valuable time reloading to get good accuracy at a low price.
Well I think most people on these forums can agree that the .17HMR is a very niche bullet.