An age-old question with many discussions and no definitive answers. Please do a search here to find previous topics.
If you believe there should at least be a "switch" in preferences to flip the polarity of the y-axis, you should put in a feature request.
Why are the 0 xy coordinates for PS and ID in the top left corner of the page, but in Illustrator, x-0 is at the top left, but y-0 is at the bottom left?!
Why aren't drawing programs and page-assembly programs identical in every regard?!
Why do we even have separate drawing programs and page-assembly programs?!
I swap back and forth between drawing programs and page assembly programs all day long every day, and have no problem whatsoever dealing with their Y axis directions. But the default for a drawing program SHOULD be the Cartesian convention, even in drawing programs which offer the option (which Illustrator does not).