I think people "hate" on Berkeley for a few reasons:
1) lower LSAT scores than peer schools
2) "hippie"/1960s reputation
3) grading system (pass/high pass/honors)
4) as compared to peer schools, seemingly lower success in biglaw
5) poor facilities compared to its peers
I think (1) is true and can't really be debated. However, they have every right to pick and choose how to accept people. It's ultimately a diversity issue. Berkeley wants to be diverse, but fact is that minorities tend to not do as well on standardized tests (LSAT, SAT, etc) as non-minorities. To get around this, they emphasize GPA instead. Berkeley has some limitations as a state institution with Prop 187/209, which banned affirmative action at least for undergraduate admissions. I don't know whether or not this extends to the law school. However, I'm guessing that it plays a role.
I think (2) is wayyyyy overblown. The Berkeley student body is much more conservative, middle/upper middle class than it used to be. This trend will likely continue with tuition hikes, effectively making it harder and harder for people with lower socioeconomic status from coming to Berkeley.
(3) is less of an issue now that more and more schools are doing this.
(4) seems to still be an issue. However, Berkeley Law students claim it's a matter of self-selection. Berkeley Law students tend to want to stay in Northern California and San Francisco/Silicon Valley aren't the biggest legal markets outside of the IP/Venture Capital regime. Then, they face stiff competition from Stanford and to a lesser extent Hastings within that market.
(5) is in the works I understand. However, as it stands, Berkeley's facilities are atrocious compared to the remainder of the T14.
Re: Berkeley's high tuition, yes, this is partly related to budget cuts. However, another part of this is due to Dean Christopher Edley's initiatives to make Berkeley a more competitive law school. This includes faculty recruitment, Berkeley's awesome LRAP program (up to $100K in benefits), and improved facilities. All of this costs $$$ and so tuition costs have been rising. California's budget woes only exacerbated the problem.
Re: Berkeley's prestige in other departments, that's really not any grounds for comparing law schools. Although law schools are named after the school, they are largely independent of the university at large aside from the name. So-called "public" law schools (Virginia, Michigan) receive very little, if no, money from the state and operate effectively as private law schools. There is some interaction with other departments, but honestly despite all the talk of "interdisciplinary" programs at law schools nowadays, it's very way overblown.
(Note: I went to Berkeley as an undergrad.)