The people of any country can/should be able to express frustration about the way their country is going, from the worst capitalist hellhole to the most underdeveloped/overexploited third world country to the pioneers of actually existing socialism.

The real measure of the validity of their criticism is what solutions they propose.

An impoverished person who has deeply suffered under Cuban/Venezuelan socialism might be deeply angry at their governments' inefficiencies and decision-making because that's what they can potentially influence, and yet also realize that the vast majority of the fault lies with Western sanctions and also refuse to join in with attacks against their governments from abroad and not wish for a coup. They should be listened to.

That same person could blame socialism and desire the US to overthrow their government and institute a divine and treat-filled capitalism, like that imagined by many in the final days of the USSR. They should be fought against as much as possible.

There's also the fact that many of the people from sanctioned socialist countries that Westerners talk to either a) had enough resources to escape their conditions, which generally would align them with anti-socialist forces, or b) were forced to escape their conditions using what little they had because otherwise conditions would be horrific and/or they would die, which would generally pre-dispose them to not liking the government for allowing that situation to occur. And also, different regions inside countries can experience widely different levels of development. So people from underdeveloped places would speak of slums and poverty, leave the country as refugees, and denounce the government to everybody they met, giving them the impression that the entire country is underdeveloped and shitty. Whereas a person in a more developed region would be getting by fairly okay and not seek to leave, but we never hear their opinion because we do not visit them.

So we aren't exposed to an unbiased sample if we don't actually live inside those countries, which most of us do not.

Think about how much respect you would give to an American liberal's complaints about American politics. It would have to be based on the content of what they are saying, what sources they use, and so on, right? They don't have good and correct opinions on the United States just because they are American. And many of them may express being very upset that a cheetoh is in the White House or whatever, failing to recognize the political mass of violence that is little different between e.g. Trump and his Dem predecessor and Dem successor.

Most of the criticism I have heard from Venezuelans in my orbit IRL are literally boomer Facebook rumors spread on WhatsApp to people here. Years-old videos presented as new. Stories about what someone's cousin heard from their friend.

It is actually more respectful to treat Venezuelans just like anyone else, just like you would treat people from your own country, and to expect them to support their ideas if they want you to believe them. Ask questions about where they heard info. Ask them to send things to you. If you know something is false, tell them. Compare incidents to voting lines in the US that are so long that people with responsibilities or health issues (I.E. most people) can't stay in them and therefore cannot vote. Do they use the same terminology consistently for these cases? Are US elections stolen by autocrats, in their minds? Etc etc.

PS depending in the class breakdown of your social circle you may be experiencing a highly biased samplr of Venezuelans. A disproportionate number of those that I know learned their politics from English-speaking Reddit and know basically nothing as a result. Just absurd propaganda narratives. People, liberals, just like anyone else.