Even worse is, that a high producing coder with just a high school degree can easily outearn someone with a PhD in ancient greek language by a huge factor. Considering that people who studied ancient greek are most probably receptionists in such company, this will cause a lot of problems in the long run.

Maybe full transparency would solve all those problems (eg. all paychecks are public), but i know people who prefer their paychecks private, because of otherwise modest lifestyle, their landlords would increase their rent, and random family members would come begging for money.