Interesting point ... I used to ask for this a lot out of books. Though at the advice of some stronger players, I've been learning to suck it up and actually grind into positions and hold them in my head. In theory, it seems monotous and you may find yourself stuck on one single page of a book for hours, but trust me, this form of "keep at it, don't ask for a crutch" training is worth it.
If you want to make it easier on you, it might help to go after books that throw diagrams after 2-3 moves. This allows you at atleast start building your visualization skills little by little.
This has always bugged me about chess books as well. I am sure that there are plenty of poeple that can look at a serious of moves in text and quickly follow along, but frankly I find it a bit outside the normal expectations of a human being to cross reference back and forth from a text move encoding to the board visualizaton.
Would be really helpful if there was an automatic Demonstrate or Visualize feature that would key off of move text similar to how a modern website can pick up on a url and let you click on it. So in the below text it would highlight the move text and let you click on it to preview in a popup dialog or even just override whats going on in the current mentor board.
This is the move you had to see when playing 20...Nd4! Black won easily after 23.Qxc3 Ne2+ 24.Kg2 Nxc3 25.Rxb7 Nxa2 (Why not? Now it's three pawns.) 26.Ra1 Nc3 27.Ra5 a6 28.h4 Nb5 29.Ra4 Rab8! 30.Rd7 (30.Rxb8 Rxb8 31.Rxa6 Nd4 followed by ...Nf5 is easy) 30...f6 when the threat of ...Kf7-e6 (winning the trapped Rook) ended matters a few moves later.