Only they can say for sure, but my short and pretty wide answer is the audio engine. Simply put I know the effect but I don’t know the exact mechanisms in black and white, only what I’ve pieced together from empirical tests and similar solutions from other fields in computer technology, mostly 3D graphics and free-roaming world-building. These things have an impressive lot in common although they might appear very different. An awful lot regarding effective programming is about cheating the hardware as much as humanly possible, and every cheat will have a trade-off of various degrees of acceptable. If you wanna see some seriously impressive works there, then the Amiga demo-scene from the mid 80’s to the early 90’s was downright bonkers in finding shortcuts to the best effects on the limitations of 500kb memory and a single DD disc to distribute it on.
I think it’s pretty safe to say that no DAW ever has actually wanted to affect the sound through the engine, but that it’s simply an unwanted side-effect that they’ve had to mask as well as possible. Some do it better than others, suffice it to say I’m not friends with the character of Audition for instance. Too dull and bassy. Which means it’s great for checking mixes in, which is what I use it for.