Disagree with the bolded part only, the rest is a lot of "what ifs" which are hard to agree/disagree with, as are any "what ifs".
It is a "what if", but you also need to look at things logically. Pakistan's record against the top teams in ODIs has been embarrassing for years, and India has been a top team for much of this decade. It is only logical to assume that had we played regular bilateral cricket in this decade, they would have won more than us, even if we entertain the possibility that we would have raised our game against them.
WC losses to India of course hurt most if they affect our prospects of winning the WC in a big way. This was true in 96, 03 (maybe?), and 11. Do you really care or even remember that we lost to India in 1992, or 1999? Yes it would be great if we won all WC games, or in fact all games period, but I for one felt the loss in 96, 11 and to some degree 03 much more than the others. This is only for fans who's ultimate goal is to win the World Cup, if you're the type of fan for who the ultimate goal at the World Cup is beating India, then yes you're probably suffering.
That said, and as I mentioned, it's highly desirable to win all games against your arch rivals. So it sucks for us that we didn't win the other 3 WC games. But it sucks for them that they have -20 (or whatever the margin is now) H2H record.
So what if it was Sharjah cup, or Asia cup, or some bilateral series -- do you think India showed up to those games not caring if they won? This is international sport my friend, no one wants to give an inch.
I agree that the World Cup defeats that resulted in our elimination hurt more than the ones that didn't affect our prospects of winning the tournament. However, we cannot disregard the other defeats because our 100% losing record against them in World Cups is very, very embarrassing.
Pakistan vs India is the most hyped up encounter in World Cups, and to see us fall short every single time is very disappointing. Of course I would love to win a World Cup rather than beat India, but I really think we have to end the streak as soon as possible because it is becoming a joke now.
As I said earlier, if Pakistan would have had the unbeaten streak in World Cup and India would have had a better record in bilateral cricket, no Pakistani fan would have swapped the World Cup streak for the superior record in bilateral cricket.
If Pakistan would have won more (or equal) number of World Cups relative to India, the World Cup losing streak would not sting much. However, not only have India thrashed us every single time in World Cups, they have also won it two times compared to us (once).
Hence, their 100% dominance over us in World Cups and two World Cup trophies make our 73-51 record largely irrelevant.
2 World Cups, 51 wins, 100% winning record in World Cups is a lot better than:
1 World Cup, 73 wins, 100% losing record in World Cups.
I would happily trade our +21 record in bilateral cricket for an additional World Cup trophy and a perfect record in World Cup H2H matches, and I am sure so would every other Pakistani irrespective of whether they admit or not.
If it was the other way round, we would have never traded a World Cup trophy and a perfect record in World cup matches for 20 odd wins in Sharjah, Kitply, Cherry Blossom, Pepsi, Boom Boom gum matches etc.