I don't need to think of math as New, Old, Traditional, or Common; this is math to make students think for themselves. It makes sense that 21st Century kids need more than multiplication tables and repetition. All students can buy in if we let them. Again, the link above is enough to make a Math teacher think around all the challenges.
In fact, after seeing all the access points to the scenic rivers of the Ozarks, I think I like the analogy of our having multiple access points to Math. Students might choose to fish, kayak, paddle board, or wade into the river. They might be up for a short float before they are ready to put in further upriver for a longer trip. Some are ready to navigate the eddies of some white water rapids. Our first job is just to get them off of the shore.
Then we can introduce them to all the beauties of Math.