Why does lemon flavored liquor always taste so fucked up?

So, I recently got my hands on some Natty Light lemonade flavored vodka and it’s terrible. I’ve also had Largo Bay Citron and choking it down was excruciating since it just tasted so nasty. Both had the same strange flavor. I don’t understand how you screw up something lemon flavored so bad. It should be hard to do, but apparently not. What gives?