Seems like a lot of folks are putting their Primaluna amps for sale...

if "a lot" is three listings?

Just sold my Dialogue pre a couple weeks ago. Simple matter of upgrading. Was fun to play with the different 12au7 tubes. I enjoyed it for the price point.

Just my opinion, but yes, "a lot" according to what I've been seeing the past 2 months, not just the snapshot of what's on there at this particular moment. Most of what I've been seeing are Dialogue Premiums; amps, monos, and integrateds. If you look at sales history, on multiple sights, it seemed people tried them and were moving on. I was only looking for some feedback, not really interested in 'snark'. 

I was tempted with PL gear. UA, for a few years, had NOS discontinued models under $1,000. UA advertises heavily in the stereo rags. I'm sure they are fine...I just decided to look elsewhere

It's probably to upgrade in some instances. They get good reviews, but they aren't perfect according to user reviews; they are built to a price after all, and I have personally always thought that they were ugly for tube gear. 
Admittedly, I have never heard any of it, and as another poster says, it may just be to get some needed cash. Anyway, they sell a lot of them, so there are a lot of owners out there.