Because that worked out so well for the people of Chile (under Pinochet). And Libya (post-Gaddafi). And Iran (1953 onwards). And Iraq (post-Saddam).

Whatever your (valid) criticisms of Maduro, it's important to remember that:

1. The US was intentionally starving Venezuela through sanctions. If conditions improve because the sanctions now get removed, it's not because Maduro is gone. It's because Venezuela's oppressor (the US) just stopped opressing (as much).

Let me put it this way. If I take all your people and put them into a ghetto in Warsaw and build a giant fence around it, letting nothing in or out. And I then decide to let food in once you've given me all your valuables or given up some leader and you now have something to eat, I'm still not the good guy because I later let food in after looting your people and I'm still responsible for starving you in the first place.

2. 20+ years ago the US would lie and say they're doing this to spread democracy and that the people would welcome them as liberators. This was the exact script for Afghanistan and Iraq. Even though it was all about oil they'd never say that. Now they don't even pretend. Trump has outright said that it's about oil and they're going to govern until a suitable puppet is put in place, who will let Western companies loot Venezuela's natural resources.

So good luck with the coming brutal dictatorship and kleptocracy your girlfriend and her countrymen are now celebrating.