Osprey's obsession on colour eye candy

[Orwell1984]

I've been following this discussion with interest.
From the beginning it appears to be a case, to use a metaphor, of someone going into a vegan restaurant and being upset they can't get a nice steak. Osprey books are know for being shorter, illustration heavy, mostly introductory books. The illustrations are the main selling feature of most of their series as most of their regular customers realize. A quick glance at their website shows the importance of the illustrations to their business model.
As to doing text heavy books, they have tried this. The old Battle Orders series was very text centred, with a layout similar to what the OP requested. The series was cancelled due to poor sales. It is apparent that Osprey is releasing their text heavy titles as part of their general history books, not part of their series which have a rather rigid design outline.
Osprey has hit on a formula that obviously works for them so why would they change it?