There is a genuine existential risk, and it's addressed in the best way possible. Military slavery ("conscription") is more evil than disenfranchisement, especially when citizenship is not required to live a good life. Nobody is tricked or coerced into signing up for military service. Potential recruits are even shown disabled veterans to make the risk more salient. There are no signs of racism or sexism.
Other objections are not supported by the film. There is no suggestion that the Buenos Aires attack is a false flag. I've seen people claim it's impossible for the bugs to do this, but it's a film featuring faster-than-light travel. The humans are already doing impossible things, so why can't the bugs? I've also heard complaints that there is no attempt at peace negotiations. There is no suggestion that peace is possible. It's possible among humans because most humans have a strong natural aversion to killing other humans. Real life armed forces have to go to great lengths to desensitize their troops to killing to prevent them from intentionally missing. But humans generally have no qualms about killing bugs, and the bugs in the movie never hesitate to kill humans.
The movie is an inspiring story about people making the right choices in a difficult situation. Some people look at it objectively, and some only react to the aesthetics. Those who look objectively understand it's actually faithful to the spirit of the book despite Verhoeven not intending that.