If you want to know "why" do a Google Trends search on slashdot. You see something that looks like e^-x, asymptoting towards zero.
It's pretty bloody obvious what's going on. A company has a unique asset, this asset is not making them money. I can sort of sympathize with this. You gotta pay the bills, right? So they try to broaden their audience (no quotations, I get that too). But as all the old timers have said - repeatedly - they only come to the site for the comments, and WE ARE THE MOTHERFUCKING COMMENTS. This has to drive marketing nuts, I suppose. There are a bunch of other more "fun" sites out there where idiots can blather on about crap. Slashdot is unique in that it has a highly technical/educated audience and a good moderation system (hah, I remember the uproar over the current comment system when it first came out, or was tweaked - somehow people DO get used to these things!).
I think the reason why you're not seeing Dice or whoever ask for the opinion of the current folks who use slashdot, is that they already know the answer. It's not about you/us - it's about getting new people on board. The problem is, that is a losing proposition. Slashdot's readership/writership really goes back to the USENET days of absolutely no moderation and a has a free-for-all meritocracy mentality. Slashdot has been around for long enough that I think your audience has already found you. We're already here. We are middle-aged highly educated highly opinionated nerds who have dealt with enough corporate horseshit to see through these things. Sorry about that.
There is a pretty high level of childish vitriol that permeates this site. If you don't at least throw us a few crumbs a lot of the crap that goes on at -1 will get a hell of a lot worse. Your audience will turn against you and that will drive away the folks who make the site work. There are alternatives. Christ, with the dwindling number of commenters, you could probably host a slashdot-like site on any of the many cloud server type places out there.
Tread carefully, corporate folks. And it wouldn't hurt if you just accepted the fact that slashdot isn't something that's going to make you money. Maybe you can leverage slashdot in other ways to sell other stuff, I don't know. But if you fuck with your nerdbase they will fuck with you twice as hard. I don't envy your position and I truly hope you find a solution that meets your objectives... keeping the old timers happy while injecting a few audience base. But you should probably try a new approach. Have you considered sending out a survey-monkey type thing to gauge exactly what the old timers are willing to concede/put up with rather than just dumping it on us?