I'm 6-2 and I think this is a made-up issue
1/ A lot of travel is business
2/ Business travelers sleep, not because they are lazy but because they are on tight time-lines and it is the best they can manage
3/ That few degrees reline allows your head to JUST go back far enough to sleep. It is a HUGE difference.
4/ This is a 'personal space' issue.  Look at the pivot point, at knee level it only moves a little ways.  99% of people are not tall enough for this to hit them.  They don't have shin room but that has nothing to do with reclining.

I don't know who made up this b.s. etiquette argument.  It is fiction.  Travelling weekly every business traveler I see reclines.  [survey a red-eye and I bet you'll see +80% reclining]

Business travelers don't complain about the person in front of them.  They don't complain about a lot of things, taking off shoes in security, liquids, carry-on baggage restrictions, even kids screaming - it is just part of flying.  Flying sucks. They know the ropes.