Corruption in the sports sector is linked to the political system where the entire government, from election to governance, is corrupt. This has affected the sports activities in most countries and even the premier league.
FIFA and other sport governing bodies are not left out in the corruption.
Could be the case but most of the time it is an isolated case. Now that I think of it, you are probably right, if the political system is corrupt then that means that they are tolerating corruption in other aspects too.