What the OP shows ignorance about is the necessity for the maximum generality of a concept for its adoption in science. The concept of 'pressure gradients' might be useful in limited contexts (in meteorolgy for example), but Newton's laws are more fundamental, and work in all contexts.
Its 'Scientific Method 101', flunked by most attention seeking dissenters!
BTW Mark Noble is here merely to do a bit of kibbitzing, by his own admission.
I rest my fundamental case - have it your way.
My condolences to your students.