It's not "cutting corners". It does take more time to build an webapp that works without any JS.
If it takes more time, the final product costs more. The client should be aware of that and make the decision. Why should he/she always pay for something that will only be useful for a very small % of his/hers clients?
If it takes more time, the final product costs more. The client should be aware of that and make the decision. Why should he/she always pay for something that will only be useful for a very small % of his/hers clients?