Having the mind to stop corruption is not easy in a nation that corruption is seen as nothing, making an attempt to do so some politicians will do everything to frustrate the agenda. Do you think a genuine president can easily end corruption of this level ?
Even that president is going to declare an all out war to the corrupt officials, it won't be that easy. It's like you're pushing a heavy boulder but there's the an obstacle that stops it from doing so.
It's hard to accept that those corrupted politicians will do everything to remain at their positions. They've been milking money to the government with their corrupted ideas.
They know how to hide their corrupt activities while sitting on their positions. That's the sad truth that corrupt countries despite there's a strong will of a good leader. There goes the other officials that won't stop what they've used to do.
In fact, there is no point in imposing the responsibility of eradicating corruption on the government alone. The whole world is plagued by corruption. About 90% of the people in a country are corrupt. Where everyone around the president is afflicted with this incurable disease, it is never possible for the president alone to eradicate corruption. Either he will become addicted to corruption (there is no saying, "It is bad to be with the bad") or he will have to be blindfolded to take action against corruption and eventually be forced to resign under pressure.
Like this guy: Jose Mujica: The world's 'poorest' president
I'm not from that country and I've only read articles that seems to be giving him the positive outlook based on what he has done. Giving 90% of his salary for the benefits of his constituents is a noble act as a president. But whether he does good governance or not, there will always be the bad side comments about leadership and this is in general, for all leaders.