You guys are really over-exaggerating Berkeley's undergrad competitiveness. For starters, regardless of what ME's "official policy" is, there's basically no way the average is 2.7. Basically the only classes that average a B- at Berkeley are weeder math/sciences courses, and the first few classes in tough major sequences. You can look at the grade distribution and see that even in the toughest majors (ME included) the averages are basically a B, with electives being closer to B+.
Traditional "law school majors" follow a similar pattern though with higher means in general. Weed the uninterested students out with a B- average in intro math/intro to X, and then basically give a B+ average for upper div electives. Also, I'm pretty sure average undergrad GPA is around a 3.4 so its not insanely low.
Furthermore, the median student is likely much better off than the mean suggests. Looking at grade distributions the median appears to higher almost always, since the people getting D's and F's are skewing the distribution.
Shows grade distribution by class/professor: https://schedulebuilder.berkeley.edu/ex ... FL/2013/93
Also, you can look at some grade inflation trends here: http://www.gradeinflation.com/
Given the right major, a high GPA from Berkeley is insanely doable, though its going to be really tough to accomplish this in engineering/hard sciences.