This too was asked.
vtiger never thinks along these lines. This is an entirely new dimension of thought. We write whatever makes it work. I know that there is some analysis behind this but I have no idea whatsoever.
I only know this – To be Big, think Small.
vtiger is working on making the code-base smaller so that it is easier to maintain. Down the line, it will consist of a small core and the rest will be pluggable to the core. This will help in modularizing the product and it will not remain a monolith as it i is now.
There will be a facility to add/integrate extensions. There will also be a facility to switch on and off the modules.