This is a business decision rather than a design decision.

There is a cost to providing a version of the website that works without JavaScript (or Flash, or Silverlight). The **business** has to decide whether the loss in revenue/visitors is worth it or not.

So if it costs $10,000 to do write this version (the number might be on the large side, but it's there for this example only) then will the business recoup that outlay over the lifetime of the site? If not, then don't provide that version.

However, if it only costs $100 to write this version then it would make sense to provide the graceful degradation.