Quantization only works if the researchers know exactly how it was done while analysing.
If you quantize, for instance, birthdate by month, and then analyse births by day of the week, you're going to get false results.
If you group your zip codes, then analyse by latitude divisions that intersect your groupings, again the results will be meaningless.
Hopefully the results of these would be obviously weird. But other quantizing may not be so obvious and missed.