I totally agree. Accessibility is a tricky thing, and a lot of products must necessarily start out not being accessible. With a startup lens, accessibility can become really costly when done too early. That being said, there may be some minimal standards that should at least be considered. Adapting a product for screen readers can involve some effort, but adapting a product to make sure colorblindness won't affect the user experience is a much lower bar.
For the first sentence, if we don't want to remove it, how about "will aim to meet social needs and strive to be accessible."
The second part is equally frustrating to me from a product perspective. In general, software products should seek to serve the 80% of its target audience whenever possible, not the 20%. It's just not a reasonable standard when thinking about developing a product that's for-profit. If I developed products with this rule in mind, I would constantly be making choices that make the least sense for the majority of users and might end up with a sprawling, settings-filled product that, well, no one would actually like.
If we're talking about essential products and systems, like government-run websites or tools, then I would agree with this statement. Tools that we have to use should be held to somewhat higher standards.