Chances are however, maybe in five years 7 will be replaced by whatever version is out. The Win32 coding environment is just inherently flawed security wise while WinRT is rather solid as of now, although WinRT needs further expanding on. Just one of several reasons why any company should move from Xp to 7 is obviously UTTERLY better security. In the future, Windows 7 won't cut it for security and with the way Windows is being released/updated every year or so now, third party developers might be less inclined to support elder systems.
Nah, there is nothing "wrong" with win32 "security." Indeed, because of Microsoft's efforts, Win7/8 are the most "secure" mass-market OSes it's possible to buy. Your assessment of WinRT is way off, sorry to say: the only "security advantage" RT has at the moment is that almost no one is running it and therefore almost no one is actively trying to hack it...
I mean, why should they? What's in it it for the RT hacker?
OS X is much the same. Apple continuously rolls out security patches in every OS update the company releases, exactly after Microsoft's example, but so many fewer people and companies use OS X than use Windows that it scarcely generates the same degree of publicity and interest that Microsoft's monthly updates generate.
The huge, practically insurmountable advantage Microsoft has presently with Windows is that it dwarfs the third-party hardware and software support of every other OS shipping on the planet; every Linux distro, every Apple OS that ever shipped, OS/2 (r.i.p.), Solaris, etc, ad infinitum. That's what makes Windows so much more compelling a choice by such a wide majority of customers, in case you were wondering. But it's those very same advantages that also incite the interest of the great majority of hackers, who don't waste their time hacking OS X when hacking Windows automatically provides them with 20x the potential target base--and WinRT is such small potatoes that it doesn't even register on the hacker's "wanna'be" scale...
So far, at least in my opinion, Microsoft is equal to the task. If you keep your Windows 7/8 box patched up to date (once a month), and you run Microsoft Security Essentials in 7 (a more robust version of MSE is built into Win8), you should never be troubled by "security" woes. I know that's been true for me for years--can't remember the last "nasty" that got me, it's been so long ago.