I wouldn’t read too much into these things. A lot of factors can influence these numbers. For instance, I imagine that Stanford’s lower 25th percentile is largely attributable to the number of student athletes Stanford has. Stanford puts a greater emphasis on athletics than many peer schools and as such may have more recruited athletes and/or more recruited athletes with lower test scores. Other factors, such as how much a school values diversity, legacies, etc., can also play a role.
There is simply too much complexity behind these numbers to tell a simple story about how much a given school values the SAT. It is also difficult to even speak of how much a given school values SAT scores because any two admissions officers at a given school will likely value the SAT to different degrees.
Practically speaking, you should aim for the school’s 75th percentile. If you are up in the 75th percentile, your score is certainly good enough for that school. For most applicants, the bottom 25 percent is pretty irrelevant to consider, as most applicants are not recruited athletes, underrepresented minorities, development cases, etc.