I've just read an article in Slate about a parent who opted her two daughters out of standardized testing. The bottom line is that the schools strongly resisted her decision with oddly unconvincing reasons. She had to contact the state board of education to get the real scoop. It didn't change her mind.
When my daughters were in school, I sought ways to get them out of standardized tests. It wasn't that easy in my state (North Carolina.) As I began to consider home-schooling (for that reason as well as others), I learned that, during the month of May, I could not form a homeschool--just to prevent me from skipping end-of-grade (EOG) tests.
Clearly, my husband I were not the only parents who hated high-stakes testing. Not only are the tests nerve-wracking and high pressure for the kids, but they also became the main focus of the entire school year. Teachers taught the subjects that would be tested, and ignored the subjects that were not.
I didn't want grades/ scores/ numbers to be what defined my children. We homeschooled both of them for high school. Mastery of material and enjoying the process of learning were our focus.
The girls took their SAT / ACT with their age-peers--with zero preparation. None. No SAT classes. No ACT prep manuals. No looking online for practice questions. I work them up the morning of the examination, handed them a pencil, and drove them the testing center. That was all. My daughters did very well on those exams, proving that the missing of state EOG tests had no negative impact. Both girls got into the colleges of their choice without any problems.
I know that this decision isn't possible for all parents. Top-tier colleges may look askance at students without a transcript from a bricks-n-mortar high school. Homeschool was a huge time commitment from me and my husband to homeschool our daughters. It wasn't cheap either. But they've thrived since--and haven't missed out on a single goal because they skipped standardized EOG testing.