I genuinely don't understand how anybody who has actually read the stories in question can think that.
The DS9 MU arc was very explicitly tied in with EVERY ongoing arc in the current DS9 books. Cardassia, Bajor, the Dominion, the Ascendants. The events depicted also had profound effects on Kira, Sisko, Vaughn, Dax and Taran'atar at the least.
It is only because of what happened in those stories that the Ascendant arc has finally kicked into action.
It's been barely a year in story time. A crapload of stuff has happened in that time - too much in my opinion. That's why I prefer to think of it as actually stretching stuff out over two seasons.
And it's been less than a month since the departure of the Founders in Olympus Descending. Exactly what do you think could have happened in that time?
Your lack of satisfaction with the pace of the stories is nothing to do with the quality of the stories themselves. It's purely the "fault" (if it can be called such, which I say it can't) of the speed with which they can be written and the ongoing drama at Pocket.
Besides, look at the amount of world shattering stuff that happened in any one season of the show that you want the books to hew to so closely. At the most there was one or two major galactic events per season. You tend to forget that it took seven years for those stories to fold out, and lots of stuff not all connected happened in the meantime.