In my honest opinion, and not trying to rile people up, because as everyone knows, that is completely out of character for me, but the only people who hate PES are the people who are shit at it.
My mate hated PES 5, because he couldn't do sweet FA in it; he couldn't score or defend, blamed the controls and traded it in for the edition of FIFA for that year and has stuck with Fifa now.
Blaming your inabaility to adapt to new nuances and additions to the gameplay stating it to be 'clunky, slow and glitched out' is basically admitting that you cannot adapt.
It is not the games fault. How can it be that bad when so many more people love the game than dislike it? Surely they'd have experienced this crapness as well? Or wait; maybe they did when they played it, but after 5 minutes, they got used to it??
I've been playing Pro Evo since ISS Pro Evolution on the PSX, and I have never blamed my wankness in the first few matches on the game, but accepted that i'd get better after a few goes.
I missed the first two (ISS Pro and ISS Pro 98) purely because I was an N64 gamer and ISS 64 and ISS 98 were the games to play at that time. However, when we played Iss Pro Evo we never looked back.