The existing service left Victoria fifteen minutes later and fitted in well with passengers who finished work at about five. Not everybody can throw downs their pens, (if indeed these are still used these days) and stomp off to the station. Many people work in synchronised work environments - shops, universities etc. Many passengers also have destination end obligations - collecting children for nurseries, etc. - connecting buses. In these austere times, the bus network out of town tends to close down earlier that in the inner city so if you miss the last one ( insert expletive of choice here) . People build their lives around their journey to work, pay good money for their journey to work and not unnaturally get angry when changes are imposed on them. I suspect come timetable change day there will be a maelstrom of discontent expresses about not only Southport services but many others for exactly the same reasons.
Frankly, tough.
People have known for two years, since the new franchise came in, that there would be changes. They have been, and continue to be, publicised effectively on the Northern website, through posters on stations, on social media, and in the local press. Large city centre employers (and many small ones) have been and are being sent specific communications, and TfGM offer a contact centre to advise customers and business alike on travel options.
Some people will lose out in some ways (me, for example, as my morning train is now either 35 minutes earlier or 30 mins later). However for almost everyone the net benefit when all of the changes are in place will be overwhelmingly positive.
People can whinge all they want but quite frankly I don't think it's justified.