The world was a different place in the early days of NT 4
Arguably true... but only for the monolithic win 9x series releases, which aren't relevant to this topic since the NT kernel was developed independently within Microsoft by Dave Cutler from DEC. It was Microsoft's first truly modern operating system. As many comm enters above me have mentioned NT originally did have functions such as font rendering in userspace due to its heavy hardware abstraction. As the pending issues with 9x loomed however MS could read the writing, on the wall; porting 9x to Unicode (it was ANSI throughout, a separate "Layer for Unicode" had to be used to run Unicode programs on 9x machines) as well as supporting newer hardware (AHCI, USB, true Plug and Play) was going to be nearly impossible (the attempt was called Windows ME). So Microsoft began with NT4 to prep for the mass migration from 9x. Since the average consumer at the time didn't want to drop $3k for a workstation that would be able to run the NT model correctly, Microsoft made some compromises to the OS for the sake of speed.
No, it wasn't. NT4 was released in 1996. By that time, many people here on
NT4 already had a security architecture. There was a different place available (basically anywhere outside ring0) and it should have been put there, and it definitely should have been obvious to anyone with three grams of brains that stuff like this doesn't belong into ring0.
You however are making the assumption that everybody in Microsoft talks to each other. A most incorrect assumption. The reality is most likely that WinDiv (The division responsible for the OS) made the assumption that fonts would not be loaded from insecure sources, e.g. Word documents. The Office division however faced the problem of what do you do when some user uses a font that is not on another users system? So they made the decision to allow the embedding of fonts into the file format, along with a bunch of other really bad decisions in hindsight (remember the Melissa virus?) that would have been caught if they had had the same security reviews as WinDiv did. To compound the problem, Office used unpublished and most likely unhardened APIs (it probably still does in parts) that allowed it the capabilities to do things like on the fly font loading something that wasn't exposed to the rest of us until Windows 2000 (NT 5.0). My point being that at the time it WAS a safe decision as far as WinDiv was concerned. Should they have been a little more careful with those unpublished APIs... yes they should have, it would have prevented a lot of anti-trust issues, but they weren't. So here we are with yet another security bug.