...in some places they are not recognizing minorities, children from impoverished backgrounds, etc.
This type of allegation/accusation must not go unquestioned. Can you name even one place where a student is not recognized as gifted based on minority status and/or impoverished background?
Please clarify, did you mean to say:
Public schools which do not have gifted programs may tend to occur more often in areas with fewer students who tend to qualify for such programs, and these areas may tend to be impoverished.
Public schools which limit their number of gifted seats to fewer than the number of pupils who qualify as gifted may tend to have disproportionally smaller number of minority students participating, when fewer minority parents sign up for the gifted seat lottery. Bear in mind that there are levels of gifted, differing interests among gifted children, and differing parental viewpoints (including various degrees of hothousing, pushy, competitive, laissez-faire, free-range parenting styles).
And on the subject of athletics, the public school system generally is not growing elite athletes. Most of that comes from private opportunities that may allow you entrance to an elite public school team (high school and college), but if you want to grow a hockey player, a swimmer, pretty much any sport, you have to private pay. The government does not have a program to search for athletic talent and grow it.
Rather than focus on the hyperbole of elite athletes and lack of governmental talent search for them, it seems that the OP is speaking of everyday situations. For example, most public schools offer sports teams at both VARSITY and Junior-varsity (JV) level, to appropriately support and grow the level of talent inherent in their student body. The sorting by athletic ability tends to be done without regard to quotas or private pay opportunities, and recognizes natural differences among students which may provide an advantage in a particular sport.