That said, accessibility is something you do when you're a big company. When you're a startup, work on making it useful to the easy customers, and then only once you have something that lots of screen-reader people want to use is it worth investing time in making it usable.
I think we would heavily disagree on the "healthier" status.
Accessibility is a legal requirement in the UK, and while you're right it's unlikely to come back to bite you as a small company, that's also a pretty crappy attitude to take. I don't like the practice of deliberately breaking the law anyway, but deliberately breaking the law requiring equal access to people with disabilities is awful.
There's an opportunity cost for everything. The most fundamental opportunity that you don't want to miss is building something that lots of people want; if you don't accomplish that (and it turns out to be really hard), it doesn't really matter how well you've built the thing that nobody wants.
Why are these the only three options?
The point (of both my comment and the original article) is that there are trade-offs, and you get to choose which trade-off you're going to accept, but anything you do is likely to piss off someone, so choose who you piss off wisely. Do you want your top priority to be accessibility? It can be, and that could be a wise choice if you identify a task that really really sucks for disabled people. But if you're looking at that before you've even got the fundamentals of building a useful product down, you risk building something that does something nobody really wants to do but does it really well.
If you run a website in North Carolina with $15k MRR accessibility is likely a waste of your time unless you're in a niche that is in some way related.
However, it remains the right thing to do, and much easier if implemented from the beginning.