For something like a government website, I agree. Access for everyone (except maybe a really unreasonable case) should be a priority. For the average web app, I

For something like a government website, I agree. Access for everyone (except maybe a really unreasonable case) should be a priority. For the average web app, I think it would hold the developers and the users back. If half a percent of the web can't use your SAAS, that's fine. If you're developing a product initially - go for the masses.