False. There is plenty of dispute about the NPV of all future dividends and the discount rate, but the notion is a fundamental truth. It is follows from basic math and is provable.
Okay, but that's not what he's claiming. He's claiming that NPV is derived exclusively (and rationally, and perhaps clairvoyantly) from the future sum of dividends.
The value of the stock is the current estimation of that npv. How it is estimated is irrelevant. It is the group estimation across all buyers and sellers.
I feel like you're taking part in some unrelated discussion. This entire discussion started because jcampbell claimed that NPV was derived from the sum of future dividends. (Actually, he claimed that stock price was NPV of those future dividends.) No one here seems to be disputing that stock has a NPV. They're disputing jcampbell's claim that NPV is derived exclusively from future dividends.
You're arguing against a claim that no one is making.
The sum of all the cash flows related to the stock (discounted for time). Dividends are not the only factor there. For most investors and most stock, the future sale price (i.e. when I sell my share) is the major factor, and any dividends are a minor factor.