You may want to use a pseudonym for work where you cut corners and failed to do work you're actually prepared to do properly. I browse without javascript enabled to judge the quality of the tools I'm considering; I wouldn't hire anyone with a portfolio full of broken non-semantic documents.

And whilst a vanishingly small percentage of people were using Mozilla, why not? If Mozilla wanted to get people to use it, it had to be compatible with (most) of the existing web.

Similarly, I won't be testing my websites in Soguo or Yandex until more than a vanishingly low percentage of people are using them on those sites.

Do you have any statistics to back up your assertion that it's growing? From what I've seen from my own anecdotal experience, as well as from access logs from past places I've worked, this minority is vanishingly small (<0.5%, even among those using screen readers it's ~1.5%) and shrinking by the day as more mobile devices support javascript.

Regardless, there is no right or wrong answer in general, there is only the right or wrong answer for your particular website/market. If a significant number of the users you want to support have JS disabled, then by all means, build a site that runs without JS. But it's a cost-benefit analysis. For most sites I've worked on, the cost of lost business due to users without JS is (massively) dwarfed by the added development cost of building a full-featured app that doesn't require JS. If that means I lose you as a customer, I'm not losing sleep over it.

No we will not lose many more. The percentages who actually did something about flash very minuscule and we would lose more by not supporting IE6.