I'm going to start by saying it's unfortunate that we, as a society, seem incapable of having a civil debate about anything without it devolving into an argument, replete with name-calling and insults. Internet forums seem to have made things worse.
The OP's original question "A question that one might ask or eventually ask is - is a digital piano a piano?"
COULD have the potential for an interesting debate, in that I believe the underlying premise is attempting to define "What is a piano?".
Without attempting to be too exhaustive, I define a piano as what I believe "most" people visualize when they think of a piano: A musical instrument that produces sound by hammers striking metal strings of different lengths, those strings being strung on a harp, with the hammers being actuated by a set of "keys". The strings are capable of being dampened or un-dampened to control sustain. It can be played softly, loudly, and anywhere in-between. The shape of the piano doesn't matter; grand, upright, box, spinet, etc.
Based on "my" definition of what a piano is, I'm going to say "No, a digital piano is not a piano, regardless of the fact that "piano" is in the name".
I own two digital pianos, along with some VST's, that I enjoy immensely. I would love to own another acoustic piano (notice I'm intentionally leaving out the word "real" here). However, for me an acoustic piano comes with too many tradeoffs in my situation (living arrangements, amount of maintenance required, cost of acquisition, etc.).