I think your parent paints a rather extreme picture. The two examples they picked, Wiehre and Herdern, are the upscale neighborhoods with plenty of mansions, and there's rather only one area with large concrete housing blocks (Weingarten). As usual, you pay a premium for the top locations but in terms of quality of living and "greenness" there are many other good spots.

Freiburg has many commuters working in Swiss pharma industry around Basel for the much lower cost of living so you should be ok as a single working in IT. If you even find housing, that is.