Having corruption does not mean you are not sovereign. Just look at how corrupt both Congress and the Senate are in the USA, esp with regards to "donations".
I'm not one to pass judgment, but I will within this context. I'll start with the basics of what is understood by people, society, and state. When a PEOPLE live in a TERRITORY and, under a LEADERSHIP that supports and claims it as their own, and this is recognized at least by the neighbors, we have a NATION-STATE; this, by the LEGITIMACY conferred by the same people, exercises SOVEREIGNTY over that area.
A state whose "elected government" exercises TYRANNY to such an extreme degree that about 1/4 or 1/5 of the entire population has to flee, and those who remain, mostly because they have no way to escape, must submit to all kinds of abuse, LEGITIMACY is what is lacking; without it, SOVEREIGNTY is also gone.
Let's recall the events that end up explaining the current situation in Venezuela: the opposition tried by force, and not even the leader, Óscar Pérez, was spared; they massacred him while he tried to surrender; They tried with protests and threw armored vehicles at the population; they tried with the vote, and the election was blatantly STOLEN.
So, of course, the people have legitimacy; but, since they are systematically prevented from exercising it, who will do it in their place? In LATAM, who? The OAS? Militarily, it's like NATO, the US + the rest; the UN? Russia and China would obstruct any resolution that approved military action.