Let's talk hypothetically. I see a nice tasty piece of DX pop up on the decode list - let's say it's Hawaii or somewhere quite difficult to get from the UK. I'm running about 10W which, as far as I am concerned is about the reasonable limit (I might occasionally go up to 20W on 160m when it's silent and I know I am not getting out). What almost invariably happens is that a station nearer to the "dx" will call at the same time, and our friend only gets one decode - the stronger one. So I wait till next time. And so on
This makes working pile-ups in JT65 (an odd concept, I know, but it does happen) almost impossible. I've watched one or two and, what happens often is an arms race. The combatants are blissfully unaware of each others existence. All they know is that they are on frequency and the guy isn't responding. So it's a little tweak on the power. After two or three goes the power is quite clearly, shall we say, large, and neither party has got through. Progress is only made when one of the pair gives up.
Compare this with CW, where one can work split, and the callers can (and do...) smear out along a portion of spectrum so that the DX can pick them off one by one.
Now I have a low boredom threshold. I listen to CW pileups and maybe have a halfhearted go, but I don't stand much chance with 50W and a LW. I *can* work DX in JT65, but it's frustrating because there are unscrupulous players with large power knobs.
So, make it your New Year Resolution to support the DX Code of Conduct
The DX Code of Conduct
And, if you want a sad and slightly different tale, try reading Randy Johnson's piece here