All users don't have the same value. And it's also about trends.More and more users use addons that block javascript by default,just like more and more users use adblock. You might not care today,but when it's time to care, well your competitor that cared will get the users and the revenue lost because "you didn't care".
supporting no script is as simple as not abusing javascript in the client.I fail to see how you'd spend more man hours when not investing in these full client-side javascript frameworks when your product can work without using javascript to begin with.
Do you have any data to back that up? In my experience it seems like the number of people who turn JS off by default has declined since SPAs became so common. It looks like the search trend for Noscript has been gradually declining since 2009, while Adblock has risen: http://www.google.com/trends/explore#q=noscript%2C%20adblock...