Is that disclaimer really needed? As someone who watched the series the first time last year, the acting and humor seem fine for TV honestly. The CGI dated of course but not offensive either.

If anything I found the later seasons more disappointing than 1 and 2 as smaller scale stories are replaced with moving the big plot forward, which still feels rushed somehow.

The disclaimer is just based on my own opinion, so inevitably there will be people to whom it does not apply. Some of the acting in season 1 is great, I would just say there are some spots where it kinda briefly falls through the floor. It may be just because I have seen it several times so am spotting things that I wouldn't have first time round.

With season 4, I believe what happened is that towards the start of production JMS was told there would be no S5 after all, so he put all of S4 and S5 into S4 ... but then there was an S5 after all!

I have a bunch of friends that either never made it completely through Season 1 or complained all through Season 1. Season 1 is rougher than normal. The problem though is that while it is easy to tell people "Skip Season 1 of TNG or DS9" (which is relatively common advice for both shows), Season 1 has so many moments of character building and foreshadowing that pay off in later seasons that even the "worst" episodes are hard to tell people to skip.

An example not quite off the top of my head is as early as Episode 2 "Soul Hunter". It's a goofy plot full of weird pseudo-scientific mysticism with a "special guest of the week" who basically never returns (excluding books and movies), so in most shows meets several definitions of skippable, but this episode also introduces Dr. Franklin, has several key Sinclair and Garibaldi moments, provides background lore for the Minbari and foreshadows certain Minbari things to come.

That's just the second episode of the season. (Truly a rough start for some.)

Another common example is "TKO". It's a silly boxing match episode, much of it doesn't do much for the series except set up some of Garibaldi's goofier side and maybe foreshadowing Garibaldi's flaws. But it's also the Ivanova confronts grief and her heritage episode, a key part of Ivanova's arc.

When I re-watched B5 a few years ago, I wad surprised by the amount of humor and small pieces of situational comedy. It’s really missing from most 2000s TV dramas, everything became really serious after 9/11. If there’s humor in a 00s or even 10s "self-respecting" drama series, it’s usually dry, dark, and/or ironic.

Completely unnecessary, yes. Babylon 5 is a product of its time, as is everything, but it is as fine a production as any other sci-fi-on-a-budget show from the early-to-late 90s. It’s a phenomenally intricate and interesting little universe with great characters and stories. No need for a disparaging disclaimer such as that.