I think that you are confused about a earnest question vs a rhetorical question.
Seriously though, we software developers should never miss an opportunity to ask "how's that platform-independent Java working out for ya?" so that the business guys remember why they need us.
It's also not true that platform independence hasn't been achieved. It's just that we call it "open standards". There are many examples, but in terms of a full application stack, HTTP/HTML is probably the best. Sure, it took the w3c and browser makers a (very long) while to get down to business, but we all stopped testing every change in 5 different browsers about 5 years ago and a year or two ago we got vector graphics and 3D when HTML5 became broadly supported.
The only remaining question is why Apple, Google and Microsoft all insisted on making smart phones and tablets entirely new beasts, incompatible with each other and with the modular, cohesive, loosely coupled web-based application stack that is obviously the clear winner for just about everything else (sorry embedded device guys).
And No, I'm not suggesting mobile browsers throw out the security boundary and let untrusted code do anything it wants. But a mobile device OS could have been just a web browser on steroids and an "app" could have been a single-archive-file website that did have access to the filesystem, the network, etc. after appropriate signed-code checking, user notification/acceptance and maybe even OS-vendor approval.
To be fair, it's no mystery why it didn't go that way. That slimy goo you find oozing out of your phone isn't a defective battery -- it's Steve Jobs', Larry Page's and Steve Balmer's drool which flows more freely when they hear the word "lockin" than if you gave pavlov's dog a real T-Bone. So thanks guys. Thanks for learning nothing at all from the PC marketplace. Thanks for saddling us with yet another set of crappy technology stacks. Thanks for laughing at us from your expensive yachts where you have your personal secretary do all the things that need to get done while we sit here cursing our "smart" phones because they simply don't do enough, don't do it right, don't talk to each other and are generally designed for you to collect data about us rather than to help make our lives easier.
I hope all of your yachts sink and you're eaten by sharks (lava-sharks in Jobs's case).