Now when I say "large", I'm not kidding. A hardback book of over 400 pages and weighing about 5 pounds (costing $99 USD plus shipping).
And while they may very well be excellent rules I personally do not want anything that huge (and presumably complex). As I've aged (I'm now 65) I find that I very much prefer relatively simple rules. I do not need the large volumes of extensive rules that so many companies seem to have favored over the past decade or so.
For my Colonial gaming I have gone back to using "The Sword and the Flame", which is around 30 years old now . . . but which still provides a good fun exciting skirmish game.
For my recent 16th century gaming, I'm using Clarence Harrison's "Victory Without Quarter" rules, which only take a handful of pages.
And for my 18th century gaming, I use fairly simple rules that I've written myself . . . which can pretty much be played just from the Quick Reference Sheets.
All of these provide me with enjoyable gaming experiences WITHOUT needing hundreds of pages of rulebook . . . so why would I want a rulebook that weighs 5 pounds?
If YOU want these huge rulebooks for your games, that's fine. I have no objection to your playing (and even enjoying) such extensive rule tomes . . . but they are not for me.