At which point in his career was his 'chance' exactly?
Agreed. The best car he had was the 07/08 BMW's, but they were only the 3rd best cars and still a relatively fair way of McLaren and Ferrari at the time 
Yup. He never got a shot in a car that could win races.
He gave the lead to Kubica in Canada, he should have fought. He could have won as he took 2nd comfortably.
That's probably got a lot to do with why some people don't care. He fundamentally lacked the drive to win
You followed F1 long enough to know there's more then more then "lacked the drive to win", it has a lot to do with finding the right car. Button was lucky to get Brawn GP and win the Championship, did he "lack the drive to win" with McLaren?, from what I see he still had the same desire but not the right car to get him on the podium. F1 is the pinnacle of Motorsports and to "lacked the drive to win", you wouldn't be in F1 for so long like like Heidfeld, Massa, Ruben, Webber, Trulli, etc.. LOL when I hear people say "well you know he doesn't want to win"

These guys are taugh and trained competitive sports at an early age.