A7 can do it? sure. but then even Notepad can do it with a lil help of gcc. yes it's exaggerated, but face it: if you have to alter value x, add feature y with dll z and spend 500 hours of coding power to get an industry-standard feature like usable real time shadow mapping into acknex, or even replace the renderer (like SPHERE for a6), you could almost as well start with notepad and gcc.

it's not a question if you could do it, it's a question of - how easily can i use it? how fast is it? what does it cost? if you are not a hobbyist, not playing around with a toolkit for fun but to realy finish a commercial game, and you are developing to a tight schedule, why would you make games based on an engine where you would have to code anything pretty yourself? how efficient would that be?

you could walk all the way to china, for sure, but if you can go there by plane, what would you decide for?