This comment flies in the face of actual history. While your point about Microsoft may be right (who knows with how they’ve ruined their messaging platforms?) it certainly doesn’t hold true for iMessage which came out in roughly the same timeframe as WhatsApp (2011 vs 2009).

iMessage still has yet to come to other platforms, and at least for a few years after the iPhone's launch, many people viewed it as a luxury product and were unlikely to spend the money to get one compared to cheaper phones (which WhatsApp supported).