I have things I specialize in. I'd say my "forte" is small stream fishing and hatch matching on larger waters.
That said, I don't limit myself to just that. I may not be a great high stick nympher, but I do it when the conditions call for it. I can enjoy tossing streamers around high and muddy water now and again. I may have little experience fishing huge rivers, but I'm not opposed to it. And I may be a complete newb when it comes to the fly rod in the salt, but I continue to hold it as a possibility and would very much enjoy doing it under the right circumstances.
I'm not a big green weenie guy either. But there's a few in my box and I have used them, and there have been situations where they were deadly. Yes, a green weenie is just chartreuse chenille wrapped around a hook. Nonetheless, by representation, it's somewhat representative of a number of different natural food items, just like the Adams' and Wulff's of the world. SJW, IMO, is in a similar category. And egg flies are actually EXACT matches for natural food items.
These flies are not in the same junk fly category, as say, pellet or bread flies. And even then, I really have nothing against junk flies. It's fishing, we do it for fun, and our adversary has the brain the size of a pea. These flies don't do any more damage to the fish or fishery. Lets not pretend like it's nuclear physics. There's no "proper" or "improper" way to do this.