"No!" Blasphemy! "I'd never put on a suit and look like crap!" Nor would he want to. Even if he did want to, which he never did, he simply wouldn't be able to. It was physically impossible, Barney was sure of it.
"Putting on a suit isn't just putting on clothes. It's..it's.." How else could he describe it than, "Suiting up!" It was important.