It's not a valid answer. It's FUD. Not saying the whole post was useless, but that part in particular was a bit lulz-worthy...
The question really should be why are people with WP7 phones still carrying their Android/iOS/whatever device everywhere they go.
Microsoft needs to ask this question, because it would really be useful for them to gauge where the most important functionality holes/disparities lie.
Every feature isn't equally important and I don't expect a feature that only I and a few others find useful to get implemented before features that a majority of users find useful...
But they have failed to reach out to users in any factorable manner and while this is a good thread and it has a good purpose unless Microsoft is reading it and/or soliciting information from it it's simply not going to do much for the platform as a whole - though it will answer the OP's questions (which is the intended purpose of the thread, so nothing wrong there).
From reading the OP, he wants to know the best way to find a middle road where each phone is more in sync than out of sync, and it's impossible to do that right now because in many cases the apps don't exist, and WP7 lacks a decent HTML5 browser.
Example: The SkyDrive website crashes almost every Android browser I've tried to access it with - Maybe Opera Mobile 11 works now, I haven't tried. But before, Firefox, the Stock Browser, Opera Mobile (10), and every browser that is derived from the stock browser crashes. If Mobile Office Solutions like ThinkFree had hooks into SkyDrive, this would be less of an issue...
Google services just aren't a pleasure to use on WP7 outside of Mail/Calendar/Contacts that sync via EAS becuase of the lack of an HTML5 browser and WP7 doesn't have Google's apps on it. Google Reader Mobile Website is a better experience than most of those third party applicaitons, and things like Google Listen just don't transfer over well to WP7 if you're a hardcore Podcaster. Google Books has a ton of Public Domain books that are useful for research purposes and the like, but it doesn't transfer over well without an app or HTML5 browser.
There's no EverNote or Catch.com applicaiton for WP7... Again, no HTML5 browser. Bringing IE9 Mobile ASAP can actually allelviate a lot of the app/services issues, TBQH... and allow users to interop with more services they have as holdovers from using another platform...
Most WP7 IM clients do not support MPOP so it's impossible to use whatever phone you'd like to IM people. It signs you off everywhere else. A client like Trillian for Android doesn't do this, but this app isn't on WP7. Since it lacks an HTML5 browser, it's hard to use web-based IM clients as well. You're forced to try to use them in desktop mode and that just doesn't work well... On the flip side the MMS client is really only half an MMS client.
It's hard to do this (interop Android and WP7). You have to make clear boundaries determining what tasks you will do on what phone and what tasks you will do on another. You have to make concessions. That is why those of us who are double fisting an Android/WP7 phone really DON'T want to do it, and would like to actually drop the Andorid device. If we hated WP7, why would we bother using it AT ALL? The Andorid phone does everything it does, and more. UI differences and preferences are purely subjective and anyone can get used to that after suitable amounts of usage...
It is not a good user experience to carry two smartphones. The reason why so many people want their companies to get rid of Blackberries and allow Android/iOS/etc. devices is precicely because they already have a smartphone and they're simply tired of carrying two everywhere they go.
Post balooned, sorry...!
We should try to get Engadget or TechCrunch or someone to take a poll to see what features people want in the OS and gauge where the most important feature disparities are. Microsoft will likely read that, but I don't think they really care about what any single or few customers say here and there...