Not knocking them or the people who like them, but they really don't do anything for me.
It isn't uncommon to have your personal favorite species in bonsai... and so the corollary would be that there will be some you like a whole lot less. I know some folks who love deciduous, and I'm not sure they have any pines at all. Ryan Neil has an extensive background with conifers, and not a lot of experience with deciduous - so I have seen him bring in visiting pros to share deciduous knowledge. I happen to dislike succulents, but some people have quite a collection.
However there is something in your statement that suggests you aren't a real bonsai person if you don't keep Japanese black pines. You shouldn't feel that way - just like you shouldn't feel bad if you don't keep huge bonsai, or shohin, or forests, or literati... I could go on and on. Do what you enjoy, and it will show in your work. If you feel "forced" to work on a tree you don't like, just because you feel it is "required" in order to be considered a true bonsai enthusiast, I doubt your tree is going to be that good
Though I keep a little bit of everything, every now and then I fall out of love with a tree. I usually solve the problem by putting the tree in the back of my garden and letting it grow unchecked for a number of years, or I trade it away. Never force yourself to work a tree you don't love. Sometimes I find that after a few years, the tree doesn't change, but I do, and I end up loving it again