twitter bootstrap usage

Total newbie question but why isn’t the twitter bootstrap framework a direct theme import into WP? I know there are numerous modified versions for WP but I am leery of many of the constructed offerings till I learn more about the potential for malware & unintended hyperlinks code to exist. It is a bit frustrating to have to be so guarded about malicious tools/code while trying to learn and offer something beneficial to readers.

I was hoping to start with a fresh twitter bootstrap implementation to ensure that things I didn’t want were not added.

TIA, Chief Foodie