Raw admission rates are insufficient to make that conclusion, since the characteristics of the applicant pools may differ. What you really want to know is, for what range/level of applicant qualifications, would a student be significantly less likely to be admitted to EECS versus L&S? But there is insufficient information for outsiders to know the answer.
Most students who go to college do not earn as high grades in college as they do in high school.
Considering that half of the students in CS 61A and 70 do not earn B+ or higher grades, earning the needed 3.3 GPA is not trivial. Somewhat more students in CS 61B do earn B+ or higher grades, but that may be because there is some overlaps with AP CS A that they may have had in high school, and the worst performing students from CS 61A deciding not to continue.
Of course, at some other universities, it is much more difficult to get into the CS major if one attends without direct admission. CMU, UIUC, UCLA, UCSD, and Washington are examples.