You're the one on the verge of swearing to be fair. He pointed out your misunderstanding of the purpose of a telescope (to see things we need to see, rather tha

You're the one on the verge of swearing to be fair. He pointed out your misunderstanding of the purpose of a telescope (to see things we need to see, rather than things we can see with eyes adapted to the heavy brightness of Earth) and that your complaint was unfair since you can always just build it yourself if you like to look at yellow featureless balls in the Earth-adapted light spectrum you enjoy. No need to call him an "ass" over it, just apologize politely :)