“Were they in the office” seems a much lower quality signal.
Attendance might not be a perfect proxy, but this is way worse.
Also outside of 80s cop dramas the line "but dammit I get results" does not overrule all other employer concerns. If instead of disregarding an attendance requirement an employee instead decided to disregard a safety requirement, would you give them a pass because they got the job done? How about if they mishandled private customer data? Made unauthorized purchases with the company credit card? Made a bigoted comment about another employee? Someone can be a high performer and still be a bad employee that an employer ought to let go.
Many managers (at least the good ones) try to shield their folks from the uglier nuts and bolts of upper management. They would far rather focus on results rather than pressuring their folks to meet some arbitrary (and likely not even mathmatically correlated) goals around butts in seats.
Is Amazon in trouble? Are they really this willing to tighten the reins on their workforce for...what? Numbers that technically show people are showing up?
The ugly truth is that Amazon is probably just looking for ammunition to fire folks en masses without it being seen as a mass layoff.