I think it's unfortunate but I can understand it's appeal and why people like it. Anyone can turn a crap photo into an appealing image with the application of a filter. Who wouldn't love that? It's like MSG for photography.
It doesn't bother me nearly as much as poorly done High Dynamic Range images. . .
Well, a maybe better comparison would be some sound effects heavily used in the eighties. I don't know nothing about photo, that's why I ask, but about sound I know a bit more, and there you have two kinds of effects:
1- The normal enhancements you are not supposed to hear. Maybe a bit of reverb or compression. For these effects, in my experience, the proper way to tune it is to turn the knob until you hear it, and then turn it back half ways.
2- The exceptional strong effect that is part of the sound. Here, you should turn knobs to their max, it will make a different sound.
The "instagram" plague looks to me like if everyone in every music would suddenly add 150% of one type of reverb, and everyone would blindly think it is great, and in two years none of these will be heard (seen) without laughing.
It doesn't bother me nearly as much as poorly done High Dynamic Range images. . .