It seems quite low I think. Part of the problem is that Android is just so ubiquitous. As the article mentions "Developing for Ubuntu Touch right now is not easy, mainly because of lack of documentation and examples". Android has a million examples, libraries, first and third party documentation, a load people at Google improving the tools all the time (though this churn can also be a bad thing of course...) Canonical has less of this and the development plan seems focused on Web apps.

Another problem is that there are no Ubuntu phones currently available to buy new. The Meizu mentioned in the article is no longer sold, and installing on semi-supported hardware is flakey. For example, you can buy a Meizu phone that has Android and reflash it with Ubuntu Touch, but then future OTA updates don't work and you have to reflash each time. Devices sold on ebay might not be the so-called "international version" and therefore have a locked bootloader, you don't know until you buy one.

The way updates are handled and the community support seem much more organised than with Firefox OS though. That was a complete disaster, with the first gen ZTE phones receiving no updates at all and even the Flame (a developer device) being pretty much abandoned right away. At least Canonical keep pushing OTAs for the official BQ and Meizu devices, and builds for Nexus devices are still produced so you can flash it on semi-common hardware if you're feeling brave.

I know it's easy to say and very difficult to do, but really what Canonical need is a phone that has some long-term availability. You often hear Alan Pope on podcasts use the excuse that it is not Canonical's problem that devices are not being sold, it is up to the manufacturers. But if there are no devices to buy then how is UT ever going to gain any real traction?