What a crock. Google has many legit reasons to not want to build an app for a competing platform, so be it. But to think a company that routinely throws money away on tons of other development efforts while letting search ad revenue subsidize the cost would suddenly start doing a cost/benefit analysis of such a trivial effort is absurd. If your formula was applied to other products, like Google Reader which was never monetized and had huge infrastructure costs, they never would have seen the light of day. This is a strategic stance on Google's part, not financial, nothing wrong with that.
Yeah, it shares a codebase with the Windows 7 version if it's different at all. The number of Windows 7 + Windows 8 installs is far greater than Windows Phone users.
Youtube is considered core mobile functionality, like a browser, but Youtube is a fiefdom in which Google does not have to compete (unlike the ultra-competitive landscape of the Browser wars). While Google has nothing to lose and everything to gain from restricting access to YouTube, the same cannot be said about the Browser, thus they compete.
It's simple economics; don't waste money helping people dethrone your monopoly (I AM NOT ADVOCATING THIS POSITION, SIMPLY STATING MY PERCEPTION).
that is a naive world view. Google has never viewed its product with such simplicity. THey are created and destroyed by a vision (sometimes bad vision, most time good vision) (sometimes in good competitive spirit, sometimes in the view of stifling competition).