[nerdawson]

That seems like quite the leap and will more than likely result in you being escorted off the plane when you reach your destination.

It may well be an inconvenience to you if someone chooses to recline their seat but nobody owes you an explanation. Expecting them to justify themselves to you isn’t a reasonable stance. And given that you don’t know what someone is going through, whether they have a hidden disability, whether they’re in chronic pain, I really wouldn’t advise asking, let alone shouting at them.