the user testimony about cinnamon 2.4 on debian testing means that providing intermediary transition isn't that hard.
You're doing people a disservice by depicting Betsy (i.e. Jessie "current") as being better, more stable and more reliable than LMDE. It certainly isn't.
We don't just maintain LMDE, we also happen to develop Cinnamon. I think we know what we're talking about here.
If we were to open the tap and freeze you yet another UP, sure you'd get updates.. but you'd also see quite a lot of regressions. Think about it like that: LMDE passed QA and release. Betsy is nowhere near achieving that.
You can be productive and talk about real issues (we fix them often, you might have seen updates for Firefox, flash, ssl, bash..etc), or you can continue to throw quantities (10+ months, 400+ issues) and security terms to vehiculate concern amongst peers and give people the idea that LMDE is some abandoned unreliable broken piece of history people can no longer use... to me that looks like FUD though, or if it's not deliberate, like misguided obsession.
There's no question 17.x is ahead right now. What it achieved, no UP can do. Betsy will get much closer to it. But make no mistake, right now and until we (and Debian) are done working on it, LMDE is a much better system than Jessie/Betsy.
Finally, from a technical point of view, note that other than timing and quality there is very little difference between UP9 and Jessie. They're both snapshots of the same release. Don't be eager to get something that isn't ready just before it becomes stable. UP9 would be what exactly? GTK 3.14 with Cinnamon 2.4 without all the fixes? Some broken Jessie missing the final touches Debian fixed just before it moved to Stable? You can already get all that by moving to Jessie/Betsy... and that's alright if that's what you want, but please don't tell everybody else that's what they need, that's just bad advice.
LMDE users will upgrade to Betsy and it WILL be a better system then, when it's ready. It isn't yet though. When that happens we'll be looking at 2+ years. Maya was released in 2012, it stopped getting new features in 2014, got outshined by Qiana and Rebecca since and is stuck with Cinnamon 2.0. Do we look at it as some sort of abandoned-ware? Do we consider removing download links for it? Do you hear us say it's more 10+ months old so let's trash it? Are you kidding me? There are distros out there which roll on bleeding edge (Arch, Debian Unstable), and there are OSes out there which rely on static 3rd party executables so you can always run the absolute latest version of anything you want (Microsoft Windows). People who value bleeding edge and version numbers more than stability, maturity, release management, should of course prefer these distros and operating systems over frozen releases such as Mint and the upcoming LMDE 2. That's not what we're doing though.
I'm sorry you probably don't agree with me on that, but I look at LMDE and Maya with pride, not just as historical/past pride, but actual pride. I'm happy people use them and I consider them good systems. The fact that we released newer versions since does not change that. Similarly, I might be excited when I work on Betsy, but I don't wish or recommend for people to run it. If you tried Cinnamon 2.4 on Jessie and you're happy with it, good for you. You might not fully understand what we do other than developing Cinnamon and using a base and that's ok.. but take my word here, Cinnamon 2.4 is out, Jessie is almost out, Betsy is not ready yet. We've got plans, we want to make that base as good to us as Trusty, we want its quality to raise to the same standard and I really don't care if that takes a few more months or so.
In the meantime LMDE is a good system, its latest release was great. I understand people want new stuff, and it's coming. Until that happens, it just needs to be stable, and I'm pretty sure it is. If there are particular issues that need fixing prior to Betsy, let's talk about them and we'll address them. This isn't a number's game though. We support LMDE, we're proud of it, we're working on its new version and yes it's true.. we're not as concerned as you are that it's 10 months old or that it'll be a year or so when Betsy comes out.