I object to paying tax to fund a taxi service for drunks.
Though Boxing Day trains aren't by and large taxi services for drunks. I used Merseyrail yesterday, it allowed me to do a "run out, train back" type thing. No need for it really but it was a pleasant morning. OTOH, I travel north to my family and back on Boxing Day each year by car, it'd be by train if there were any, and on the way back the M6 and M1 were busy - plenty of demand for the WCML there.
With regard to Christmas Eve this year, it was a special case - because it was a Saturday most who would normally travel on 24th did on 23rd.
With regard to staff being forced to work - for a reduced service like that on Merseyrail you don't need everyone, so if you make a good enough offer people will work. My Mum used to happily do Boxing Day in a bank call centre for, if I recall rightly, triple time (or may have been double + time off in lieu). And my observation of Merseyrail yesterday was of cheerful staff who were running a short day of easy, slackly timed services very much without the drunks (with the "fun" aspect of being able to run fast like the "big" railway). It didn't give the impression of people who didn't want to be there.