CBS-D certainly has people with the passion to do DS9 in HD right; they just need the go ahead (and the $$$) from CBS corporate to do that.
It's first and foremost the money they need. That's where the crux lies. Right now it seems that TNG in HD isn't doing as well as we first thought it might. There was a bit of a hype with the first few seasons and 1-3 consistently ranked within the top 100 blu rays at amazon even several months after their release. Look at season 5 now, it's nowhere to be seen let alone the previous seasons.
I think it was Frontier Trek who mentioned when season 1 was released that it cost 9 million to remaster. That's 63 million for the entire series. This is a huge amount of money they need to earn back before they even start making a profit. I'm optimistic it will happen in the long term some day. However, I'm not convinced that's a popular business model in the entertainment industry. As a result, it seems doubtful at this stage they will green light DS9 or Voyager which have far less recognition than TNG and, therefore, would take much longer to earn a return on an investment.
9 million was the budget for the whole project, not just season one.