Not always.
Writing a shocking scene is also an art, and even though I completely hate that it happened, I will say Loeb completely succeeded with this scene.
The rest of Ultimatum is poorly written, but he got exactly the reaction he was going for there, and so it actually was quality writing.
I'm going to respectfully disagree - getting exactly the reaction you want does not equate to quality writing.
I wanted my friend to laugh, so I farted. He laughed. That just isn't quality humour, but he laughed anyway.
Given Loeb's writing, I even think this ANALogy is appropriate
There is an art to 'shock', I agree. But shock can be accomplished without art as well. Its what separates 'Alien' (IMO, a movie of 'accomplished shocks') from say Boogeyman 3, where the nature of the shock is, in part, a disbelief that they would stoop to that level of graphic ineptitude. Both movies sought to shock. Both did. Only one is good.
Loeb obviously stooped to that level of shock to generate talk - he knew he wouldn't be able to generate talk via a good story, or any decent characterization, so he settled for what he always uses - cheap, over the top garbage. If anything, Loeb accomplished what he wanted (buzz) by producing something completely devoid of creative quality. Even poor art would improve his work... as it is, you look at the pretty pictures and add 'what a shame' to his resume.
Loeb's basic premise is: I can produce boring, or I can produce 'shock'/garbage. At least the latter gets talked about.