My instructor introduced me to the term. If I fly by moving from one feature to another, I'm track crawling. Do it in the skills test, I could well be looking at a failure. I just hope the CAA examiner I get isn't reading this
I hope you don't fail because of "track crawling" if you planned on doing a bit of track crawling. As somebody said: if you follow a very easy to distinguish feature to stay clear of controlled airspace and/or other hazards, why not?
Two example: In the Netherlands it is perfectly normal to follow the coastline from Hook of Holland to Den Helder. Very scenic, and it keeps you perfectly clear of both the Rotterdam and Schiphol CTRs. The coastline curves slightly, so you start out heading about 030, ending up due North. DR would take you several miles offshore and with the Schiphol TMA starting above you at 1500', not much chance of gliding to the coast and setting up a decent forced landing approach somewhere in the dunes.
Another example is flying between DET and OCK in the SE UK. If you do DR, or use radio nav, you fly straight through the Biggin Hill ATZ. Whereas if you track along the M25, you stay clear of everything, including the Gatwick and Heathrow CTRs.
So if you plan to use track crawling as your primary navigation method, with possibly another technique as backup, it can be the most sensible method of navigation, depending on circumstances. I can't see your examiner faulting you for it. Me personally, I combine satnav, radio nav, DR and track crawling depending on the route, and may change techniques several times within one single flight, depending on the requirements for each leg.