It is therefore "notional" dividends/ retained profits which underpin market value in the same way as notional property rental values underpin property prices, with "Buy to Let" as the arbitrage.  

There's a big difference between:

(a) making Profits - and not paying dividends for tax reasons; and

(b) making losses - so there aren't any profits to retain.

Most DotComs were profit free zones, some without even GROSS revenues, never mind NET.