when a player retires, he's giving the rest of the match to his opponent
That is true, and I do agree with that. I mean if we are counting the match, then the SR should count.
If a match is counted when a player wins 3-6 4-6 0-4 ret, the only possible way for him to have won that match was to come back and win the next three sets. The ratio would HAVE to have been 3:2. And if we are counting him as the winner we should count the ratio he would have won by.
My opinion last night was more of an attempt to be in the middle and compromise, but given more thought, I really do support counting the SR.