Survival

A lot of actors back then mostly came from theatre so they were properly trained. Even the weakest actors back in the 70s or 80s brought a charisma missing from today's acting generation to the point you wouldn't notice that actor wasn't very good. Most of today's actors aren't classically trained so are basically training on the job which isn't good. For all the retrospective talk about how theatre acting feels staged by today's standards it had better advantages in the long run in that at least stage actors honed their craft.

I saw some of Lost, it seemed to have similar issues of events and character changes happening at the whim of the writers, and not because of narrative reasoning. You can make big changes to either characters or dynamic in a show, but you need to provide the narrative justification for it. Rather than what Battlestar Galactica did in having these things happen at the drop of a hat, without any (internal to the show) logic. I see some of this kind of bad writing in older shows, but it seems to be more common and acceptable now, along with being in vogue to have twists come out of nowhere that make no sense. They should make sense! If they don't, you are doing lazy writing. Agatha Christie is a good example of a smart writer making twists happen to preconceived characters and dynamics. She always said, that the characters would tell her, "no, I wouldn't do that," or, "that wouldn't make sense." She had to invent plot devices for her characters and setting to fit into the narrative she wanted. The characters were still in character, and dynamics and settings smoothly changed to the new formula because it made sense in their world. The end result was that she got the story line she originally wanted, and the fictional world still made sense! Good writers find ways to encourage the unnatural situation, not force it on the characters with a sledgehammer.

In Battlestar Galactica's case, they didn't listen to fans on the internet, all those bad decisions were made drunk in bars. You can see the show writers owning up to this in many interviews. They admitted that in retrospect, the show would have been better if they had been sober while writing it.  I can only excuse following internet fans for so much bad writing. Bad ideas being thrust upon you(or from the internet as you said), true, if it was a dumb idea, then it shows in how little narrative thrust you can get out of it. However, Bad execution of ideas, now that is just poor writing.