That's a good healthy response,
@mjr . Not paranoia then, perhaps just irrational feelings of persecution by motorists driving on the road behind you (as
@I like Skol has also suggested)?
Sadly not that irrational. I've had the misfortune to be on the receiving end of a few road-rage incidents in the last decade, which is a minor part of why I often use a handlebar camera.
Have I made sure I've maximised my visibility to them?
Blimey, don't fall for that old chestnut! If you're on a correctly lit and reflectored bike, you're almost certainly visible enough.
Where else have you seen these sort of "reasons against flashing lights"? You said: "and those are the reasons I've seen most commonly."
Other forums, facebook groups, the various cycling blogs I subscribe to and so on. I've not been keeping track of who said what over the last 20 odd years. Some people are pro-flashing and others are anti. Outbursts against flashing used to be more widespread when flashing headlights were still illegal on non-emergency bikes.