I'm going to refrain from taking this into the history of games tangent and just say that, at this time, D&D is primarily composed of discrete abilities, regardless of what an ideal game might be. Within the existing paradigm of discrete abilities, martial classes could use more to expand their options.
I don't believe that was ever in dispute.
My points are about what 5e already has and why certain issues aren't necessarily always due to the mechanics or supposed lack thereof.
And more to the point, having a button for pulling a Bobby Hill is just boring game design. We don't need more buttons like that.
A better way would be a core set of kicking mechanics that are then built upon by classes, feats, etc adding more choices to engaging in that behavior, with the Bobby Hill special being at the bottom of the list of possibilities. In doing this in this way, you can also then integrate with other mechanics, producing interactions that give an exponential amount more possibilities.
But, the trouble is that can quickly become very complex and convoluted if you're not careful, and meanwhile the Improvise Action option merely requires a mutually agreed upon expectation, that the books absolutely should help establish, to accomplish much of the same goal without the baggage of making a simple kick to the nuts a rocket equation.