Captain Birdseye: I know there are lots of minor key tunes. I play loads myself. What I was pointing out is that they are in a minority, and as time progressed from 1600 to 1900 they became even more of a minority. As evidenced by the fact that the more modern tunes(hornpipes) had a higher proprtion of major key tunes than did jigs or reels.
As an example, I have just counted up the O'Neill hornpipes. I may have overlooked one or two, I did it quickly, but as far as I can see there are 150 hornpipes in the book.
9 A minor
2 E minor
1 G minor.
All the rest are major(138).(I am, by the way, only judging by O'Neill's versions. For example, you refer to the variable third in Cheif O'Neill's Favourite, which is how we all play it now. But he notated it with a major third throughout).
That is definitely a huge majority of major tunes.If you fancy counting up the jigs or reels, feel free!
I would think the preponderance of major is even greater in England(at any given date), because the big swing from minor to major occurred substantially(a century?) earlier in England.
    Nowadays, on the session and recording scene, there has of course been something of a swing back to more "archaic" otr "interesting" tunes, which has shifted the balance a little bit back in the minor direction. But major tunes are still hugely in the majority, in Irish or British sessions.
   Incidentally,Captain, "minor" is perfectly standard usage for the aeolian and dorian modes, to distinguish them from the ionian and myxolydian. You personally may not term the dorian mode a minor key, but usage is against you there I think, in traditional music circles.