Theres no kind of person that would not find their place among the students at Berkeley. Nevertheless, there is a particular kind of person that I prefer would avoid tarnishing the essence of education that exudes from the Berkeley campus. That type of person is one that cares only about what he can do to gain an advantage over other students. One that forgos a hollistic learning process that combines knowledge with compassion for the desire to succeed. Theres more to education than straight A's. The heartless, mechanical minds cannot get as much out of Berkeley as others might.
People who need a great deal of individual attention should not attend this school as Undergraduates. There are bountiful resources at UCB, but you need to seek them out and FIGHT for them. Being self-disciplined and proactive is very important here, as well as making sure you don't get isolated or overwhelmed by the academics: find your niche. Being conservative and closed minded could be very difficult here, as well as lazy, or just of different priorities than ACADEMICS. You have to remember this is a school catering to Graduate Students. They won't notice you without work.
In order to understand the kind of person who should not attend Berkeley, you must understand the kind of student that does attend Berkeley. The majority of students here share similar attributes: they have a rough plan of what they are going to do with their lives for the next 5-10 years career-wise; they take academics very seriously, to the point where that might mean sacrificing their weekends to study in the library; finally, they are so goal-oriented that even if you aren't yourself, you would be inspired to do so just by being around them.
UC Berkeley has a very competitive atmosphere and classes are very rigourous. Someone should not attend this school if they have not had a rigourous course load during high school or community college. Also, Berkeley's atmosphere is fairly liberal, so having an open mind and respecting others perspective is important, otherwise if you are not open minded this school is probably not the right fit. Berkeley is in the middle of the city of Berkeley, so if someone doesn't like an urban environment then this is probably not the school for you.
I believe that UC Berkeley is for everyone, because everyone can find their own place here to feel at home. However, that being said, I would not recommend this university to people who are uncomfortable with new ideas and people. UC Berkeley is filled with diversity and it definitely shows as students will each have high developed ideas and morals. There will always be someone who thinks just like you, but ten others who disagree. Even then, Berkeley is a place where you can share out your ideas and only be greeted with respect.
Because of its immense student body population, U.C. Berkeley is not a school for the unmotivated. Those that need to be taken by the hand through a process while being served on a silver platter will not thrive at a university like this one. U.C. Berkeley is for the self-motivated, the self-driven with an ambition that creates a path in front of them of their very own. A student who is not independent and requires the constant attention and aide of higher authorities is not the type of student that will succeed here.
The kind of people who shouldn't attend Berkeley are people who don't like large universities and can't handle large lecture classes. Its part of the Berkeley experience, I believe, especially freshman year. Also, while a little bit of intimidation of the competition is healthy towards working hard for a good grade, people who are severely intimidating could find it crippling. On the whole however, Berkeley suits a large majority of people, and its all about going out there and finding your niche.
If you're going to school for the sole purpose of getting a degree, Berkeley is the last place you should be. Berkeley is for those who learn for the sake of knowledge and understanding; for development and creative expression rather than for some end goal. There's no doubt that you'll gain a degree and a financially viable career in the process, but the personal gains that you earn through the richness and diversity of experience that Berkeley offers is worth so much more than a certificate.
A person who is closed to new ideas and beliefs should not attend Berkeley. It is a very diverse campus and attracts all kinds of people from all walks of life. These people can be passionate at best and in-your-face at worst. A person who is unable to deal with these "characters" would be unsuitable for this campus. As a political conservative, I am definitely in the minority at Cal, but there are definitely clubs I can join, and people respect my ideas in class because I respect their's.
UC Berkeley is a top school, so it is definitely competitive--there are weeder classes, competition and rankings in certain classes needed for impacted majors and so forth, so if you want a more laid-back environment, either don't take those particular majors, or don't come to Cal. Also, if you're not big on getting frustrated or disappointed, don't come here either for, although there are many amazing, intelligent professors and GSIs, there are also terrible ones as well.