Tarhiel: You´re way off.
First, HBS with Shadowrun did look after Shadowrun series just as they are looking after Battletech - but they did it for free.
I'm not disputing that they offered patches after release, but I think you may be missing my point. I'm talking about the content and gameplay, which through the three campaigns marched from a short, very linear sequence of levels to something with much more secondary content and player agency. Those enhancements weren't, and arguably couldn't be, backported to the earlier games/campaigns. All of them got nice graphics updates, and that is indeed commendable, but you can't play Dead Man's Switch with the greatly improved HK mechanics (with all the side missions and whatnot) or, conversely, or send the DMS runner to Hong Kong for a second adventure. And that was the focus of my criticism, that the NWN style 'lots of little standalone campaigns' thing doesn't play well in the 2010s.
I did jump on the backer wagon with Battletech, but one of my concerns was that we'd have a repeat performance and wind up with a couple of small games that play well for the diehard fans but get buried in a landscape full of heavy hitting, high-agency RPGs. In other words, if they did Battletech like they did Shadowrun we'd have Battletech: The Arano Restoration, which has very few side missions and ends as soon as Kamea gets her throne back, and Battletech: The Inner Sphere Adventure, which plays like career mode but House Arano and your starting batch of MechWarriors don't even exist. HBS probably evolved on their own, but I can't help but wonder if some of the Paradox guys visting them in the early part of the buyout negotiations talked up the benefits of modular content. Or, eh, maybe Weisman just remembered that trying to do that with MechCommander 2 was a big fail.
And as you yourself alluded to, Dragonfall was not free to non-backers; we got it as either the standalone version or as paid DLC. Nothing wrong with that--it was a fat stack of content after all--but then I'm not arguing against paid DLC. :)
It´s not true that Paradox publishing HBS game made their game better - if anything, they monetize on features which were previously for free.
Shadowrun series: 4 major updates (1.1, 1.2, 2.0, 3.0).
Battletech: 8 major updates so far (1.x).
Stellaris (PDX): 13 major updates.
Surviving Mars (PDX): 12 major updates.
All of those update were free, almost all of them included both content and technical stuff. Paradox appears to be rather good at cranking them out; indeed, their whole business model is built around sustained long term support. They just charge money if you want an extra helping of toys.
edit: Don't get me wrong, PDX has done some pretty dumb stuff over the years like pushing their lame account system. I'm not trying to be a fanboi or apologist here. I just don't understand the complaints about the update program, because they're giving people what they say they want.