Virtuemart is great, but how about its code and architecture?

Virtuemart is the most popular e-commerce component for Joomla 1.5, the edito开发者_运维技巧r selected, total free and open source, with stunning strong power! So great, i like it. Thanks all the developers of Virtuemart.

But, my God, there is SQL query even in its themes, why, and why didn't Virtuemart coordinate MVC architecture of Joomla, and, seems no interest in re-factor to do that. It's so hard to develop base on Virtuemart.

I think there must be some great reasons in the hands of Virtuemart developers, Could anyone tell me the reasons or what the advantage of the architecture of Virtuemart ?

(Also i has the same problems with kunena, the great forum component.)

Virtuemart is a eCommerce component for joomla and to handle commercial you have to keep everything secure. Thats why we store everything in database rather storing things temporary. MVC architecture also helps in re usability of the code with higher security.