While we don't know for certain why the community has gone off the boil since the rise of templating in circa 2007. I'm sure I'm not the only one who thinks that the drift from improving articles to templating them has been a major cause.
I'm not sure that this software is really going in the right direction if it is simply making it easier for editors to do more drive by tagging of articles rather than actually improving them. In particular we need to think of the newbies in this, it is self evidently more friendly to greet a newbie by categorising and wikifying their contribution than by adding a category needed or Wikify template. I'm pretty sure the newbie is more likely to learn the bit of coding you've just added to their article by seeing what change yu've made than by clicking the links in a maintenance template and reading the relevant policy. May I suggest that like hotcat this software should encourage the patroller to improve articles not just tag them.