Ok, now I realize I was completely uninvolved in any of this, but as a UT user on a Nexus 4 for well over a month and someone who made a failed Ubuntu respin in the 2010's, I feel I can settle the question in this with sufficient knowledge and explain why this conspiracy is completely wrong.
I will explain it from a complete outsider perspective. It all started with Ubuntu Netbook edition, which was the first version that had an early version of the interface we use on our devices today. Using Ubuntu with a phone was discussed, but back then, that was obviously long before the age of full Android dominance.
Then Ubuntu Touch came out and Mark discussed the issue of convergence, which back then was like science fiction. It was great, but only worked on a couple of devices. Also decisions made for the desktop environment to accomodate the move to phones ticked off a lot of users who moved to other respins or distros (ok maybe not that many but at least me). So now we're at like 2010ish.
That was the year of the Ubuntu Edge (ok it was 2014). Mark had the idea to make a state of the art Ubuntu Phone called the Ubuntu Edge which would have made your iPhone eat dirt, plus it could do convergence, and legit believed he could raise $32M to make one on Indiegogo. He was close (ok in the end he wasn't. He was like $20M off but that first week was super exciting.) https://www.indiegogo.com/projects/ubuntu-edge#/
So finally, I think, I think the technical vision (which was futuristic and awesome) became overshadowed by the financial vision (huge profits as would-be future iPhone users would mock the green-text poors from their amazing, high-end convergence devices and was incredibly unrealistic for an obvious reason I will detail) and I feel like the Edge campaign was a bit of a wake-up call from reality.
It wasn't long before I think that took a toll on Mark, who from what I understand from what I've read of him is basically successful at everything he does. As someone who has occasionally failed, I completely understand how painful that can be, and so it's understandable why he walked away from the project and the Unity DE to put back Gnome. However, the reason the vision failed is kind of obvious: Ubuntu's popularity among new regular users is that you can bring computers whose technical requirements failed Windows back to life. In short, Ubuntu's popularity among regular users was bringing old computers back, while powering new devices was a much later focus of interest. Certainly, I have never been part of the $600 phone crowd. So Mark focused on Ubuntu Desktop and gave UT back to the community to work on. However, before the Installer, installing Ubuntu Touch looked a lot like making Puppy Linux run the latest Chrome. (No, no, it's not as easy as using the portable version.)
So they quietly have been working to put UT on more devices, which kept a lot of people under the radar interested. Librem came out and with the whole $599 pre-order a lot of people were like "oh we've seen this before." But then in the fall, suddenly this weird PinePhone company came out offering $100 phones with... Ubuntu Touch on it. Well, I may not be a tech person, but I do know that $100 minus $10 for UBports equals A REALLY CHEAP PHONE and that's the language I speak. Having raged quietly against the monster Android's become, I became obsessed with finding how these Pinephone guys did it. What's the cheap tech, I wanted to know. I wanted to know. (Also they sold out of the phones.) So I think I duckduckgo'd "low cost ubuntu touch" or something and found the page with the Nexus 4. And there was an easy installer. And bless that guy who was selling a Nexus 4 with UT on it for $80 (totally fair if you add in the labor cost) but as someone who got Puppy Linux to run the latest Chrome, that installer looked really easy, so I bought a Nexus 4 for $35 and a week for delivery and an hour later had UT running on it.
So it's not that there was a conspiracy, it's that UT only became massively accessible a few months ago and everyone's like "how this phone work so great" when in fact it's the product of years of work that no one noticed and it's only shining now.
I believe this authoritatively settles the question. I have spoken.