That's a good question Alluveal and normally my answer would be "no it doesn't matter."
As a music nerd, I've spent a lot of time learning how musicians learn their craft, reading about little facts about the process of writing, rehearsing and recording some of my favorite music; artist influences, technique, etc. But at the end of the day none of that matters unless something works right and effects the listener. The members of Steely Dan are famous for killing themselves over every minute detail while the Ramones' seminal debut was recorded in a flash for $5000 when they could barely play their instruments, and I love them both.
In movies we can learn all we want about the "making of" but no matter how impressive the details and the effort itself, we don't have to like something just because we're impressed by it. I found my interest in both movies and music revitalized when I laid off the nerdy music research and stopped watching DVD bonus features and commentaries.
But the reason the improvised nature of BSG bothers me is because the nature of the show implied it shouldn't be. The Cylons had a Plan. There were all sorts of mysteries about Starbuck's "death," the odd appearance of that song, secret Cylons, etc.
The real life works is that, if you don't know something, it's not because that thing doesn't exist yet or hasn't happened, it's just that you don't possess that information, until you acquire facts about the nature of something. Stories- fiction or not- can only work when it uses realistic logic. So the creator invents some fact, builds a story around it, hides some mystery from the audience, then reveals it to them, thus completing the story, and it makes sense and works.
Nobody's claiming every TV show should be well planned all in advance. The very nature of TV actually precludes that. And because of that, most shows don't have the structure of building in some deep mysteries that are the foundation of the plot. But IF someone decides to do that, then yes, those mysteries should be worked out when they're invented, otherwise it's like starting to tell a joke without knowing the punchline.
I think BSG would've worked out much better if either:
1. Those big mysteries were thought out in advance. Not every detail, but things like who are the final 5 and why are they secret, what is the origin and nature of the prophecies, dreams, visions, etc.
2. Left as a show about survivors fleeing an genocidal robot race in space.
That second show could've been just fine without all the nonsense they tried to throw in there. They could even have kept all their social/religious/political commentary stuff in there.
Reminds me of The X-Files- remember when that show started it was really awesome? Yet so simple- two detectives with conflicting yet complimentary characteristics investigate various paranormal activities. Fantastic! But no, they had to start with their Big Arc Mysteries, with unplanned consequences, that eventually deteriorated the show and buried it in incomprehensible and nonsensical garbage. Looks like something similar happened here.