Preston-Crewe isnt that bad, like someone said below you get an excellent view at slow speed of Warrington Arpley while departing WBQ, which is one of the highlights on any route in the UK. Plus Wigan Depot. Also the view is not just purely boring fields as you pass through towns like Wigan and Warrington. There are also the various yards around Crewe itself. The section of the WCML I find most boring is probably a lot of what is south of Crewe which there really is nothing to look at besides fields for very long periods of time.
Also found north of Preston less interesting than Preston-Crewe (with the exception of a quick look at the yard at Carnforth, which you pass very fast in a few seconds anyway, and the Lake District part which is over very, very quickly and does not visit any of the more spectacular parts of the Lake District, you really need to go by Road to see the Lake District anywhere near properly)