I think most of Motorola's current issues stem from the fact that they got sold to Lenovo ... plain and simple and their issues go far beyond the Droid line. Droids are Verizon exclusives, think of them as Verizon's version of the Nexus; Verizon designs the phone, then Motorola builds them to Verizon's spec (hardware AND software). I think, maybe, your issues with the DT2 are because Motorola stopped fighting back against some of Verizon's design choices.
On a grander scale, I saw this coming as soon as I read that Google sold Motorola off to Lenovo. The Motorola that so many people fell in love with... the Moto X Motorola... that's not Motorola, that's Google playing puppetmaster with an OEM and implementing the 'KISS' strategy on a corporate level. Develope solid phones, load a nice clean version of Android that isn't overburdened with a bunch of unnecessary customizations and then sell it for a reasonable price. It might not have sold at Galaxy S-levels, but the result was proof that you need not spend $700 to get a phone that runs really well. And to top it off, users got updates right quick.
Once the transition to Lenovo started, the first thing that dropped was speedy updates. The first major round of updates post-sale was an unmitigated disaster, both in speed and quality. What I couldn't figure out is how this came as a surprise to people. They were a division of Google, of COURSE they'd get OS updates out quickly... they kind of had an 'in'. Once Motorola went from an internal group to a external customer, there was no way to keep that relationship the same. Add in the announcement that Lenovo basically told any non-Droid carrier-based models that they are SOL when it comes to updates to 6.0, well, it was clear that Lenovo wasn't all that interested in the Moto spirit.
Then came The Purge. Back in August, Lenovo cleaned house... punting a bunch of workers, including some 500 over at Motorola... including a huge chunk of the same R&D staff that made Moto, well, Moto. I was afraid that this would happen, that Lenovo would basically capitalize on Motorola's name and then replace its inards with Lenovo people, which is precisely what happened.
Considering the long development cycle of phones, the current generation of Motorola phones most likely still have a bit of the Google Motorola left in them. What will the next generation be? Dunno....