No, I agree partial credit can be useful in many cases.
Here is why I think it is petty in this case:
assume grading is a tool to communicate degree of mastery of some concepts that are tested
assume it is better to test concepts frequently, provide feedback early, and move forward based on those results -- then there shouldn't be a scenario where there are TONS of concepts being tested (or at least not for a quiz)
if there are only a few concepts being tested, then does 2% really indicate any meaningful distinction of knowledge attained? Or is it as good as 0%? (I suppose the latter)
grading takes work. This teacher had to look hard to find something that they felt indicated a few points, but that effort has little benefit to the student -- who would likely benefit more from some remediation efforts than the teacher going through a quiz with a fine tooth comb.
the teacher using this quiz to form their next lesson understood the kid needed remediation well before finding +2% partial credit, the kid's grade is effectively the same as 0% and has no return on the teachers time investment to find this +2%, the kids morale is effectively the same as 0%, except worse now because there is an ongoing joke among their peers about the quiz. So all of the time the teacher spent grading this quiz has resulted in a worse outcome than if they just said, "wow this is bad, 0%, let's do tutoring" and moved on.
A thriller in which you, the listener, are the hero. The Walk begins in Inverness station, Scotland. Through a case of mistaken identity, you, "the walker," are given a vital package that must be couriered to Edinburgh. But as you're about to board the train, terrorists blow it up and set off an electromagnetic pulse! None of the cars or trains are working - you'll have to walk - but now the terrorists are on your trail because they want the device you're carrying, and the police are after you as a suspect in the bombing. To survive, you'll have to join up with other escapees from the city - but how many of them can you trust, and are they really who they say they are?
But it's 46% of their battery usage. If they're not using much battery this makes sense. Mine is 32% for 6 hr 11 minutes since my last full charge which is days ago.