I don't really see why people are against it, personally I never buy locked devices but they are usually a chunk cheaper and there is always an option for a locked device.
If telecoms were making certain phones exclusively locked (as in not selling unlocked phones) it would be a problem. But rn it seems that it is an easy way to save money if you like a carrier.
We do have apprenticeships! For ex: https://www.apprenticeship.gov/apprenticeship-occupations/listings?occupationCode=51-4121.00