Math is a discipline. That means it takes practice and effort to become proficient with it and to understand it. It is not something we can casually be entertained by and passively gain understanding, as perhaps art or music appreciation might be considered (though to truly appreciate these, one must practice and work at them as well to fully understand).
As society has gotten more conveniences to avoid work and more entertaining distractions, we have become less willing to build discipline within ourselves and our children. Consequently we have sought after those who would tell us that there are easier ways without practice and obedience to law. The secular educational prophets have promoted the "Constructivist" way of learning math and other subjects. They have promoted it by preaching that they are helping students develop deeper understanding, while derisively calling the necessary practice of math "drill and kill."
They have tried to make it fun and flashy to fit our lazy, entertainment-filled world. Most of the time it is merely confusing avoidance of work. When challenged they have said that parents should not interfere with the work of professionals and that they, and only they, know how kids learn "their way," as if the youth were alien beings. They have even tried to promote it saying that this is the way females and minorities learn best, which is demeaning and dehumanizing all.
To really understand math, with a deep understanding, one must first become proficient in its operation, just as with a musical instrument. As the proficiency is improved, one can come to appreciate its nuances and find ways to use it for benefit. Of course guidance will greatly enhance this. It is absolutely true that if we only practice our scales in music we will not come to appreciate music, but if we do not practice our scales we will never become proficient OR understand music truly. The same is true of math.
Because math is so important in so many fields, we must come to understand this progression in learning and seek to avoid theories that will circumvent real and deep understanding and proficiency by those who would sell "new" books and programs or seek to gain power or glory in the field of education. Constructivist ways tend to create students who stand in awe of math, but believe they will never be able to do it or really understand it. No wonder we are not progressing in the field of math!