That's not the point. Execs don't dismiss WhatsApp because it's not US-oriented enough and therefore not shiny. Large multinational companies don't have that strong of bias towards any market or they wouldn't be successful multinational in the first place. Also, who in their right mind would want to be in charge of a market leader with 2 billions users? WhatsApp is so unshiny that Will Cathcart was in Fortune 40 under 40 last year...
WhatsApp was not left untouched by the way. If you are not targeting entreprise customers, what really makes money in the messaging world is payments and WhatsApp is moving hard into this market. It's just doing so in India.