The article you are commenting makes this point quite eloquently, so I'm not sure why you think this would be an unpopular opinion?
> [...] By being less accessible, the word a11y denotes a more technical approach to accessibility, not necessarily from those who use accessibility tools, but those who create them.
> That’s why I choose to use the word a11y here, and why I choose the hashtag #a11y on social media. And I’d recommend you do the same to avoid creating noise for people looking to improve their personal accessible experience.
So for general use, I recommend against using a11y, yet I’ve named this site with this acronym. There are a few reasons I made this decision. Firstly, WCAG 3.1.1 does permit domain-specific jargon so long as it we define it. So, take this post as a definition. Additionally, I expect most people who have found this site will have found it because they are specifically looking for something accessibility related.