Why would I as an end-user be worried about how much money I will spend in future on a device?
When I buy a TV or a game console - I so surely don't worry about the future of that company. I buy it because I either need it or just want to spoil myself i.e. I want it. I don't give a rat's booty on what happens to their marketshare or their future "updates".
Of course if more people bought the same TV as me, the TV making guys will be happy and hire more people to make even more awesome TV when I want a new one(?) but I won't really care if the company shuts down tomorrow morning, because I've paid for a merchandise that I liked on that shop floor at that moment.
BTW, do we know if any of the phones (including iPhones) say it somewhere in their customer charters or T&Cs that "when you buy our phone, we aren't just selling you the hardware but also the software and all their future upgrades and promise to give you 500 new apps every month"?
If no, then why do we even care?! Whatever happens to the company or their software or app developers or swimming pools, you phone will be EXACTLY what they sold you as!
I'm still rocking my Toshiba TG01 (1st snapdragon 1Ghz stuff) with WM6.5 (came with WM6.1) and as we all know that platform is DEAD. My phone works exactly how it worked 4 years ago and I'm happy with what it does even now.
So no, I am not worried about WP or its future but I'm worried about the techo-insane society my kids are growing up in