I didn't ask if you can do those things. Of course you CAN. But a car wouldn't be good at plowing a field, even with a plow. And driving a tractor to work would take up two lanes of traffic and waste a ton of fuel. Autodesk COULD (probably?) add mesh modeling support to Revit. But it'd take a whole lot of resources, and it'd probably weigh down an already not wonderfully put together program.
The main issue here is that there are a ton of other improvements that could be made to Revit that are desperately needed, rather than adding something that you can do in another program that is specifically built to do that other thing.
I think the other misconception here, that I see all of the time, is that Revit is primarily a modeling program. Its not. Its a documentation program. It utilizes 3D modeling in order to improve that documentation. The vector based modeling that it provides accomplishes 95% of user needs for that documentation (minimum, its 100% for us).
I would not be upset if this were magically added to the program. Its just that there are dozens and dozens of other improvements that really need to be put in place that will have a far more significant impact on the workflows for all users, and doing this would cut into the resources needed for those other improvements.