Everything now seems to be so long, have so many episodes. This is 6 episodes, Gold Digger was 6 episodes (about 3 too long, with a duff, weak ending), His Dark Materials is 8 hours, and the new version of A Christmas Carol is THREE hour-long episodes.
Unless a drama really grabs me then I increasingly won't put in the time to get to the end. I only persevered with Gold Digger because I'd already invested in the first couple of episodes, and didn't guess that it would just peter out.