That article has a complete disregard for any sort of sense of proportion. Cologne and Dusseldorf are both much bigger cities than Hartlepool and Newcastle, and both lie on an Intercity rail route, rather than being somewhat on a periphery like the Durham Coast line.
As Cherry Picker alludes to and JohnB57 details, a very unfair comparison is being made. Cologne has five times the population of Newcastle, and Dusseldorf 5 or 6 times the population of Hartlepool, and there are many other routes around Britain where the comparison with Germany would work out quite differently. For example, I could compare Sunderland to Newcastle to a UK rail journey between two cities of similar influence on the other: Birmingham to Coventry. Birmingham to Coventry sees three Pendolino Intercity trains an hour, and a total of seven trains per hour between the two. Does this mean I want to see Pendolinos operating between Newcastle and Sunderland? No, it's unrealistic: Birmingham and Coventry are both larger cities than Newcastle and Sunderland, and benefit from lying on the course of the WCML. I'd like to see a half hourly service between Middlesborough and Newcastle on the Durham coast, possibly some four carriage trains and the 142s replaced with something better, but we need to be comparing apples with apples and not with German oranges here.