Something can be ugly intentionally and still be artistically successful.

Some work is meant to be difficult to look at, and it succeeds precisely by refusing to be pleasant. Beauty is one available effect among several, and treating it as the only measure would rule out most of what art has done about war, grief, and rage.

When something repels you, separate the two questions: do I like this, and is it doing what it intends. You can answer no to the first and yes to the second, and holding that distinction will make you a much better judge of anything.