Richard Feynman once wrote:
Someboody says, “You know, you people always say that space is continuous. How do you know when you get to a small enough dimension that there really are enough points in between, that it isn’t just a lot of dots separated by little distances?” Or they say, “You know those quantum mechanical amplitudes you told me about, they’re so complicated and absurd, what makes you think those are right? Maybe they aren’t right.” Such remarks are obvious and are perfectly clear to anybody who is working on this problem. It does not do any good to point this out.
The Character of Physical Law, MIT Press 1965
Anyhow, I don’t think the problem is appropriately dealt with today. Feynman may have been right that the problem was obvious, the answer apparently is not (or is it?). Isn’t it worth leaving the question as an open question rather than as a taboo question?