Anyone who has used iPad or iPhone or an Android device can tell that devices like these, not Symbian or WAP or Brew or whatever, are the future. Those other platforms might catch up, but for now they lag abysmally behind in terms of user experience. And so while they might outnumber iOS and Android for now, that numerical advantage can not last.
Walk around a Y-Combinator event (or CES, or E3, or anywhere else where leading edge alpha geeks congregate) and count phones. I'd be willing to wager a lot of money you'd see a bunch of iOS and Android devices, a few blackberries, and a smattering of ancient nokia and samsung free phones held by users who "just want to make calls" (and thus aren't going to be reachable by any apps at all, WAP or Java or otherwise).
So, yes, a company developing an app today for iOS or Android isn't going to make their money back on the platform as it stands in any reasonable amount of time. But a company or developer who positions themselves to be on top of a platform that is rising meteorically (and will displace literally billions of feature phones over the next decade and a half as moore's law drops silicon costs by a factor of 1000) is going to do well.
Hype is about future expectations. When expectations rise above exponential growth in our industry, those expectations usually turn out wrong. But the mobile market has a current penetration of over 3 billion people and I'll wager practically every phone on the planet will be a "smartphone" in under 15 years. That's a lot of headroom for growth.