Soon Chandler was let go; his drafts largely discarded. He wrote the following angry letter to Hitchcock some time later, after reading the final script.
I think Chandler just didn't "get" Hitchcock. Chandler wrote about tough guys, toughing it out in a corrupt world. Hitchcock showed us regular people stumbling into a world of hidden agendas and mistaken understandings. Chandler played with words. Hitchcock orchestrated images. Chandler likes confusion and obfuscation. Hitchcock loves irony and suspense.
There's plenty of creativity and subtext in Hitchcock's films, it's just not the sort of creativity or subtext Chandler would easily notice.
To quote Ebert:
> Hitchcock said that correct casting saved him a reel in storytelling time, since audiences would sense qualities in the actors that didn't need to be spelled out. ... "Strangers on a Train" is not a psychological study, however, but a first-rate thriller with odd little kinks now and then. ... Hitchcock was a classical technician in controlling his visuals, and his use of screen space underlined the tension in ways the audience is not always aware of. ... The movie is usually ranked among Hitchcock's best ... and its appeal is probably the linking of an ingenious plot with insinuating creepiness.