I'm hoping someone is still following this, because I finally got some
new information.

I finally had the ugly grass identified by someone who seems to know his
stuff. He said it's "wild fescue". He also said there isn't much I can do
about it (since the lawn I am trying to maintain is dwarf fescue) except
what I have been doing, which is to hit the worst spots with Roundup and
reseed.

He's probably right; but if anyone has any different ideas, I would like
to read them.