> For whatever reason, they cannot allow applications to use the existing capabilities of the underlying OS. This goes against the Unix mindset; of course there will be unpleasant consequences, but one cannot hold Unix mindset responsible for these.

Using the native capabilities of the OS in the sense you mean - allowing TeX to use its ancient, hideous bitmap font system, goes against:

- Unix philisophy - do one thing well, link against or pipe to other apps/libraries that do their thing well

- Simplicity. The user should not be forced to make an unnecessary choice where one option is almost always superor to the other.

Knuth's concept of 'bug free' is one of an academic computer scientist. TeX has many, many issues: unnecessary dependencies, a horrible build process, and many UX issues that stopped TeX from reaching TeX's original goal of 'allowing anyone to create typeset documents'. This is fine: Knuth is a mathematically focused computer scientist from a period where everyone who had access to a computer was a programmer. It was valid in this era.