They don't mean that it should never happen, they mean that given the growth prospects of Reddit they should just become a regular business instead of continuing to try to get a VC return.
VC investors indeed try to get VC returns but sometimes their bets fail and that's part of their portfolio theory.
The early investors have definitely done well already.
Investors(which includes VCs/angels,etc. AND employees) should be rewarded, whether that's the risk they take (ex. VCs) or the work they put in (employees). I'm confused where this viewpoint came from, given every business works this way -- a company gets investments (either through money or employee time) and if that business grows, so do the investments...