Like I said before, we're always harder on what's more recent because we've had time to get used to the flaws in the older stuff, to gloss over and rationalize and forgive them. The illusion of nostalgia, the way the brain smooths out the past, leading to the false perception that the present is worse.
The problem I have with this view is that unlike the past when I had to rely strictly on memory or when a network would choose to rerun an episode or film on television I can now revisit whatever I want whenever I want. I can watch an old film back-to-back with a new one or an old series episode back-to-back with a current rebooted film. I can compare the two right then and there
and not have to rely simply on nostaligia tinted memory.
But it's not just about memory of the facts. The brain constructs narratives to make sense of the world, and we have a bias toward constructing consistent ones. The more time we have to mull over something, whether it's a TV show or a personal memory, the more time we have to revise the narratives we construct to explain it to ourselves, and the more excuses we come up with to rationalize or forgive things that would stand out more jarringly if the experience were new. It's like relationships -- we learn to excuse and even enjoy the quirks of our friends or loved ones that annoyed or even offended us initially, because we train our brains to find them more acceptable -- we revise our narratives about those people and the reasons for their behavior, because we want those narratives to fit a consistent model of "person I like." By the same token, as I said, we learn to forgive things about the old, familiar Trek that we're unforgiving of in something new. We see them differently because we're applying different narrative constructs to them.