I agree that there are viewpoints informed by a desire for "equal outcomes" rather than "equal opportunities". Some people may not be ready to consider with an open mind that people are not uniform but are individuals, with unique strengths and weaknesses... however others may be ready to consider that reality.
nor that student needs are big enough to require anything beyond classroom differentiation.
A few thoughts to possibly counter this:
1) Differentiation is a
buzzword which only means
something is different: the advanced students may be required to twiddle their thumbs, mark time, march in place, tread water, or other catch phrases which indicate busy work with no real intellectual challenge or moving forward with measurable academic learning gains. With "differentiation" the pupil's school experience is
somehow different, but this term is sufficiently nebulous as to what is "different" for the student's educational experience. Too often the difference may be in work-products expected (
differentiated task demands), possibly including more stringent
grading criteria, rather than a qualitatively different instructional level and pacing.
2) In contemplating whether student needs may be big enough to be met with advanced curriculum, such as the next "grade level" curriculum... that's where this study may come in handy, in showing that 15% - 45% of students are testing beyond proficient and therefore may have readiness and ability to learn advanced curriculum, such as the next year's curriculum.
3) Lack of an academic/intellectual challenge worthy of one's potential can cause long-lasting and far-reaching problems (some of which are summarized in the recent thread
what kids don't learn).
They both think that the gifted label stems from home enrichment and privilege, rather than higher intellectual ability.
A few thoughts to answer those who may present such views:
1) Home enrichment is not reserved to the wealthy. Rather, it may be simply regarded as positive parenting. Having books on hand is a common example. Library books are free to borrow and many charities provide a selection of books free for the taking. Enrichment may take many forms, such as reading to a child, conversing with a child, talking about one's day, making eye contact, asking questions, pointing out colors of everyday objects, counting things, discussing textures, describing foods as they are eaten, etc... anything which engages and stimulates the brain in a positive manner. Building a relationship with the child and building a child's vocabulary may be two notable benefits.
2) Both nature and nurture are involved in intellect; Native intelligence must be coached and nurtured to grow, just as athletic ability must be coached and nurtured to grow.
3) From an old thread discussing gifted myths, this
post hopes to raise awareness that some conflate giftedness with opportunity, but they are two different things. Nature and nurture.
4) This
thread shows that low SES schools with high-achieving students do exist (such as Steubenville City, Ohio).
5) There are many shining examples of role models - people who've risen from difficult circumstances, including Oprah Winfrey, Dr. Ben Carson, Chris Gardner ("Pursuit of Happyness"), Carol Swain,
Candace Owens,
Phiona Mutesi and students such as
Destyni Tyree,
Liyjon Desilva,
Samantha Garvey, who come to mind as frequently cited examples.
Also that it all evens out in the end
There are posts about the heinous and toxic practices undertaken in attempt to close achievement gaps by capping the growth of students at the top, getting them to level-out, underachieve, and in some cases develop a host of social and emotional difficulties from sensing a need to hide or deny their gifts and talents (failure to embrace being their true selves).
... and everyone should have access to the same materials.
Some may wish to respond:
This is as preposterous as saying all should wear the same size of shoes! 
I'm not saying that keeping up the conversation is easy, only that it is necessary, it is up to the gifted community, and there is good company along the way. Here's an
old post which reflects on a similar theme.
