I agree the real problem with students being unready for college “starts long before high school.” Not though, with the premise that today’s school day emphasis is not stimulating and challenging. As a school board member, I can attest to the challenges our students, teachers and staff face every single day.
From increased standards, to excessive testing, to underfunding of districts, to the critical shortage of teachers, there is plenty of challenge in schools. As for the assertion that neglecting homework in favor of after school activities is bad, a 2013 study published in the Journal of Experimental Education found too much homework has negative effects on well-being and behavior and the negative effects can extend outside of school, including family, friends, and other activities.[i]
“Cultural mindset” is part of the problem, but it is that of our populace not being engaged enough elect those who truly care about our community public schools, and the 83% of AZ students they nurture.
[i] http://www.tandfonline.com/doi/full/10.1080/00220973.2012.745469
Restore Reason 
I wonder how many “problems” in our educational system today can be directly tracked to “underfunding” of public schools?
One example in this piece on challenges of schools you cite “critical shortage of teachers” to name just one. Look at all the challenges facing education and how many can be traced directly back to school finance?
If we can pinpoint underfunding as a major cause then shouldn’t we itemize the reasons for the situation? Is it because we are in a deep recession, people are taxed beyond their means to pay or other priorities have more pressing needs?
Arizona desperately requires a serious public discussion of state fiscal priorities especially in the allocation of monies toward investment in the future economic health of the state.
Will we have the educated and trained skill level citizens to bring solid good paying employment to Arizona. Is our current system of educational choices promoting the best uses of our tax dollars?
It looks to me like our whole system of public education demands a statewide discussion and review of funding priorities and educational opportunities before we dig ourselves a deeper hole and finish closing the state to additional economic growth.