Exactly. Follow the cost-benefit analysis through to completion. For my startup, it's not worth it to create a second version of the site.
I'd love to serve up the site in a way that lets any screen reader or NoScript user see the site as it is intended, but the costs are too high for the relative gains.
1) the percentage of users that have JS disabled
2) the cost associated with developing a non-JS version of your site
3) the revenue you stand to lose if you require JS
4) the aesthetic/functional impact on the user experience for non-JS users
Put all of that together and you'll have your answer. For me, it's not worth maintaining two version of what I build.