I grew up in a house where EVERYTHING was wood (my father was a builder and loved wood). Each and every room had a different wood on the walls - larch, knotty pine, pecky cyprus, ... you get the idea. Peter and I now own the house and use it as a summer home.
I now understand why I wanted as little woodwork on the interior of our boat - wood is dark and reflects back very little of the light. Living in the confined space of a boat, the dark wood made me feel as if I were a troglodyte*.
Teak decks are hot. Hot on the feet in the sun, they heat up the interior of the boat which is good if you live in Scandinavia or other northern climes, but not so much fun if you are cruising in the tropics.
Interior wood doesn't require a whole lot of maintenance - a little care and feeding and perhaps varnishing every ten years or so and it should look pretty good. Dark, but nice.
As low maintenance as teak decks and brightwork may be, it still requires cleaning and care, and more work than fiberglass. Most cruisers let their decks go gray, "natural" because they don't get to a marina with lots of water available to really keep up the teak decks. Varnish has a short life, perhaps 6 months in the tropics, before it starts to degrade and need a new coat.
Wood that needs to be revarnished because it is badly degraded and peeling must be done well if subsequent care of the wood is to be reasonably efficient. That means cleaning and sanding the old wood, applying many base coats of varnish (7, 8?) before the wood is properly protected, and then a semi-annual light sanding and application of another coat of varnish.
Or you can go with some of the pigmented synthetic varnishes, such as Cetol(tm), which give the wood a slightly artificial color.
Can you tell that wood is not my thing?
*troglodyte = "a prehistoric cave dweller" = just to hammer home my dislike of dark wood in small interior spaces
I agree that wood looks good when well cared-for, but I believe that modern materials are more efficient and suitable to a life afloat.