Please remember that it is not economically viable to do what you want, and neither is it n the player's best interests.
Sure, they could release a single huge core rulebook. and they could either charge a small fortune, and no one would buy it, or charge a market reasonable price and everyone buys it. And in both cases, the company goes bankrupt.
Which, as a player you might not care about except as a player you will find many things not balanced or could be improved with the rulebook - especially the more classes there are, the higher the levels are spread, and especially with interaction of rules, and especially with the lack of details for some geographical areas. So ever player either dumps the system or floods the internet with their rules variants.
The economically viable, and viable for playtesting the concept and expanding it, is to release it piecemeal. It's a 'proud' tradition because anyone who has done it that way has survived for a while, and anyone who has not has not for whatever reason. The original D&D manuals gave you all the basicl clsses, sure -but they lifted your paying level and released suppliments for higher and higher levels.
Also, Mongoose did do what you wanted with the last roleplayng series - the initial book had everything, a spread fo classes, over the full 20 levels, the core rules, and the whole gazetteer. The supplimetnt came slowly for major additions - the Darklands, and the further exotic magic users. And people complained that some classes weren't balancd over the level spread or with each other, or that the gazetteer did not have enough in depth information.
This time, the roleplaying game is going to be tied intimately with the single player gamebok. Therefore, instead of spreading themselves thin, the first book will concentrate on showing the whole core rules, how this ethos ties to converting aspects of the single game, and showing it with the only truly explained ad balanced class for the gamebooks - the kai lords.
Therefore, armed with this knowledge, we could happily create the other classes ourselves based on the progressions shown in the mini-adventures/companion, the progressions from the d20, or our own class ideas. And heck, we could convert our old campaign games to run with the new system if we wished.
And therefore I guess the opportunity will also be taken to expand magnamnd slowly and in depth with eac sectin concentrated on - Sommerlund or the lastands for the first core book perhaps?
Anyway, the points are stop crucifying people ahead of tme before the book is released, for the practises that have to be in place for this to be economcally viable and practically viable fom a playtesting standpoint, to people who aren't hardened evil businessmen but are actual fans trying to make a living at producing something they love and want to provide.
Wizards of the coast produce rules systems, the make their money expanding the systems for use in various settings (with rules variants) and then ocasionaly refining the system. Mongoose have the rights to intellectual properties and al they can do is apply the most suitable system to it, occasionally create their own (wich is alot of work) but basically they need to enrich those intellectual properties as a means of continued operation.
We shall see the system and the exact contents of the cre book when the system is released. Until then, taking out your frustrations abut how the economy and function of these systems on a small company is not helping anything
