No, it does not mean that anyone failed to excel at football.
The sentence seems a bit garbled, but I would parse it as follows:
Wenger fell instantly for a sport associated with
(the working classes)
(kids in school that failed to excel)
"Kids in school that failed to excel" would probably be easier to read as
Kids that failed to excel in school
Or even better, as @AndrewLeach points out in his comment:
Kids who failed to excel in school
While that can still mean they excel at sports (in an American setting, I guess), this generally means they did not excel at their academic pursuits, lowering their chances of becoming successful in life through their education.
Football, in Wenger's view, gives (some of) those people a chance to become successful in a different way.