Not that they are not popular, per se, but let me give it a try. IMO, I suppose that they are chosen or left out of choice using different parameters. For instance, if you have a small face mill that cuts perfectly, I wouldn't assume you will let it go, whatever you deal is, with it.
However, there are large-diameter face mills that measure more than 1m in diameter – mainly due to the fact that they were made in the 90’s. These are quite unstable to operate, and they can be a real pain to maintain them and keep them being accurate.