And their peers generally don't care.

Also, consider the criteria for having a paper accepted at a prestigious conference. Generally, there must be a non-trivial proof of some sort or strong empirical evaluation. This is a great way to discourage people from submitting novel ideas that are hard to evaluate.

Some means of demonstrating the fidelity of an idea - either through formal proof or empirical evaluation - is expected of all scientific and engineering papers.

There are lots of interesting ideas that don't work. The value of knowing an interesting idea does work is enormous. Evaluating ideas is the basis of the scientific method.