Maybe if you had a hospitable residence that didn't have outdated stuff in it, it wouldn't have been an issue.
Sure, you can blame the both of you on this one, but it isn't far fetched to think that most people today may not know what they can and cannot block due to people not updating their rentals to code. There's a reason those codes change year after year, let alone after decades. It's a safety hazard and honestly, maybe you should make it a point to do walkthroughs and point out the do's and don'ts in your rentals when you do rent them out.
I'd say it's as much your fault as the renter's.