I had visions of never buying another iPhone again and just using a watch, iPad, and laptop.
Much like the iPod and iPhone were tethered to iTunes and then later gained autonomy, I’m hoping they’ll get there with the watch in just a couple iterations.
They'd effectively be expending resources to make it possible for people who want a Watch to not use an iPhone. Doesn't add up in my head why they'd do that (though I'm with you, I'd much rather just have my iPad).
The reason probably is that it wouldn't be a good product.
That could change though, it would make sense if they manage to pack in enough guts while preserving the battery to make the Watch more stand-alone, no reason it couldn't happen.
The reality of the market is that either you kill your cash cow (with a hopefully bigger cash cow) or someone else will do it for you.