I agree with you. I personally am much more distracted at home because "I'm home". When I'm at work, I'm in work mode. I also find that I solve a lot of yesterdays roadblocks during my commute (20 mins each way) and the shower. Solving problems is not always about characters per second of new code.
Over the years, I can't even count the number of times that I heard a conversation taking place and was able to step in and say "that's wrong" and stop several people from a multiple day detour.
I do think 40 person open spaces are bad but small ones for a team of 2-5 that are all working on the same project are great (ideal imo), especially in a sealed room with lots of white boards, etc.
I do think that remote will become more and more common as companies see it as a way to reduce costs.
It seems like the author is mainly concerned about what is best for them, not the team. Requirements and clarifications constantly evolve. It is expensive to have every requirement exactly defined with full test cases when you aren't sure what you need to build. Being involved in that process gets everyone to good enough quicker. Also, I'm not sure what to do when a customer calls (8-6, presumably) and has an issue and the night owl is the one who knows that part of the system, telling the customer to call back at 1:00 cause that's when Bob is awake seems pretty silly.
Most tech companies have hours ~8-6, because that is their customers hours too, not out of a mandate to irritate employees. I do agree with the author that if the employer only cares about butts in seats, then it is a bad place to work but that has nothing to do with remote vs on site.