Eh, as I said earlier, it is a question of balancing easier access to the material for more customers vs reducing page count, and presumably price, slightly. WotC will ask itself a question like "will cutting the price of books by $2 create more extra sales than we'll lose from all the over 45 gamers out there that won't be able to read the book anymore?"
I guess it would be interesting to know the demographics of purchasers of different books and games, though I suspect even WotC can't really get complete data on that. I just know that I sat in B&N and looked over the PF core book thoroughly, and between the sheer obtuseness of PF rules, a small font, and the various screening and whatnot on the page reducing contrast it wasn't an enjoyable experience. So I didn't buy the product, which otherwise I might have been inclined to do.
Is there a 'compromise'? Well, maybe. I can't tell you at exactly what point size the text becomes more effort to read, or if a slightly less generous use of whitespace in the layout would make any difference without seeing it. I do know there's a difference and I suspect it is a continuum. Every move in the direction of tiny condensed text and monolithic "wall o' text" layout adds a little effort. At some point you begin to notice it and feel like you want to go on to something easier to read.
