No, it's just that nobody wants to look too closely at other big sports. The same Spanish doctor who got busted for working with a lot of cyclists was also working with a lot of Spanish footballers at a time when their national team won both Euros and World Cup. Yet, the last part was quietly swept under the rug...

the other leagues have arenas which are vehicles for bribes. Cycling events span many different regions , are not as lucrative and don't have the means to cover up doping scandals like the other leagues do.