The texture of your bread's crumb is very dependent on the protein
content of its flour; softer flour produces a softer crumb. French
Type 55 flour is only about 9 1/2 % protein(*) compared to 14% or
more for North American bread flour. YMMV but here in Canada I use a
combination of 20% soft pastry flour and 80% all-purpose flour to get
the kind of baguette crumb that I like.
Also, FWIW, a third of the soft flour in my baguette recipe is whole
wheat flour from which I've removed the larger bits of bran with a
very fine drum sifter. This produces an overall blend that better
mimics the slightly less refined white flour used in France.
Cheers,
Dan
(*) see _On Food And Cooking_ by Harold McGee