Hammer's Jealousy of Shy
I think that although Hammer appeared to loathe Shy, he was deeply jealous of Shy. Shy was a great looking guy with a nice personality whom the ladies adored. And it was obvious that Shy was respectful of others. I think that all of these things contributed to Hammer's dislike of Shy. Pure jealousy.
"Sometimes a person takes on the coloring of his associates"