I guess that depends on what the player expects to get out of the action. Personally, when I take the Dodge action, my expectation is that enemies may choose to not attack me. If the player is expecting to still be attacked, and looking forward to imposing Disadvantage on the attack roll, then I could see why they might feel disappointed.
A similar situation happened in my first 5E campaign. At level 14, the barbarian gained a class feature which automatically imposed Disadvantage on all attack rolls made by adjacent enemies against anyone other than the barbarian. For some reason, the player expected that enemies would continue to attack the other PCs, even though they had Disadvantage. Instead, it just guaranteed that all adjacent enemies would always target the barbarian (even more than they already were); which I'm pretty sure was the intent of the feature.
