Trust us, that quote is how Thompson talks (writes)
all the time. The movie could only attempt to capture Thompson's book, by using verbatim quotes; but unfortunately, it was either that or try to tell a story.
Not even Johnny Depp (who I like owing to his penchant for this type of weird role) could save it from the hellbrew of its own mad source material. (Darn, it IS tempting to try out Thompson's writing style, hmm,
OuT? )