To be fair, Linux just inherited all its foundations and security principles straight from Unix. And Unix itself went through the same growing pains as Windows.
The problem is that the Windows ecosystem completely eclipses the Unix/Linux ecosystem. Microsoft has to cater for every possibility and crappy piece of software. Yes mistakes have been made (see: DLL Hell before XP came along). But at least Microsoft are steadily improving things. UAC has always been a transitional technology. UAC will gradually change over the next few major Windows releases by becoming less and less forgiving to badly written third party software.
It's not as though Windows NT has never had the security that UAC offers. It has. It just has never been used properly on the desktop/workstation. That is the fault of Microsoft really and their pursuits of backwards compatibility. With Windows XP they had a choice... either make it as forgiving to Windows 9x applications and migrants as possible, or make it secure and compatibility with 9x comes second... they, obviously and wisely at the time, chose the former. And XP was the most successful desktop OS ever as a result.
The problem is that the Windows ecosystem completely eclipses the Unix/Linux ecosystem. Microsoft has to cater for every possibility and crappy piece of software. Yes mistakes have been made (see: DLL Hell before XP came along). But at least Microsoft are steadily improving things. UAC has always been a transitional technology. UAC will gradually change over the next few major Windows releases by becoming less and less forgiving to badly written third party software.
It's not as though Windows NT has never had the security that UAC offers. It has. It just has never been used properly on the desktop/workstation. That is the fault of Microsoft really and their pursuits of backwards compatibility. With Windows XP they had a choice... either make it as forgiving to Windows 9x applications and migrants as possible, or make it secure and compatibility with 9x comes second... they, obviously and wisely at the time, chose the former. And XP was the most successful desktop OS ever as a result.