Exactly my experience as well. Let's use a grid and the bootstrap elements!
designs come in without grid in mind, and no bootstrap elementsThough I do agree with the article in some respects. Bootstrap can be a bloat on a heavily designed site. You end up only using the grid for instance, and there are lighter weight frameworks for that.
Bootstrap is a godsend to strapped IT departments with no designers backing them though. Can really break the old schoolers out of table based layouts and nice pretty buttons quickly.
I leaned more heavily on Bootstrap when initially wrapping my head around RWD, but now that it has "clicked" in my brain, I'll be switching off of Bootstrap to something smaller. Bourbon and Neat more than likely, but I do need to look into Pure CSS too.