You can't really predict the future like that.. there were lots of mp3 players, tablets, smart phones, smart watches etc. before the ones that "hit it off" and made a lot of money. I'd think the theory is Meta has the money to invest for the long term as the market is building and become a leader.
Walkmans were big hits 50 years ago. Blackberry phones 20 years ago. I wouldn't exactly say music players and smart phones had a track record of failures.
