We can say the exact same thing about any style of colouring and shading:
If done well, with a good understanding of ALL the styles in any piece of work (be it a picture, an animation, a video game) that style can look good. It can look stupendous.
And if done badly, it can look really, really bad.
If you think any one particular style looks bad, you've either not encountered good examples of it, or it's just not for you. And while everyone has their right to their opinion, that doesn't make it "true", any more than one person's dislike for a particular colour makes that colour "bad".
:EDIT: Also, I'm confused by the examples in the first post. Is it supposed to be in favour of cel shading, or not? Because either the OP doesn't know what cel shading is, or they're poking at none-cel shading to make a point about how cel shading isn't ugly. I'm assuming the first. That example is not cel shading.