Some lines have so many fabrics, I think it'll be far to expensive for shops and a risk to have to many leftovers.
In Holland many of the shops more or less specialise.
My favorite shop sells a lot of reproductions, japanese fabrics and Moda.
She doesn't sell the 'whole' serie, but fabrics that she knows will sell Mostly that's about half of a line.
(and of course doesn't have every new line in her store that's come on the market)
I think it works very well. When I want p.e. Jinny Beyer fabric, TOT's, marbles or fabric for children, I know I have to go to another shop.
So I visit 3 shops more or less regular.
Works for me (and for them LOL)