You are absolutely correct; it's the only way they can measure easily: your attendance. Timelines, deliverables, e-mail replies, etc are the other easier ones. Determine the quality of work, leadership, innovation, efficiency, etc need proper analysis and most managers are not able to do it.
I'm finding more and more job descriptions explicitly stating that they expect the employee to be on site and working the regular schedule.
I currently have a handful of people reporting to me and I have no issues of allowing them to work a day a week from home. I do it myself. Only time when I can get some peace and quiet to get proper work done. Life is too short, commutes are too long, and don't have budget to give people raises.
I do get the occasional comments about my team and I just ignore those.