By insisting that our students go down the grammar rabbit hole with us, they build an antipathy for us and what we are requiring them to do. Their affective filters are off the chart, and actually leave our classrooms after one or two years to never return, and worse, feeling that they are failures at languages.
If an army platoon commander went into battle and quickly lost over 50% of her soldiers, she would call a retreat and regroup. She would NOT keep her troops in battle (the rabbit hole) and go ahead and lose the other half. If she had any sense, she would leave the rabbit hole and breathe the healing air.
Even the “successful” kids who stay in the rabbit hole with you for more than two years are lost, precisely because they spent the 3 or 4 years with you in the grammar hole. These are the ones who then go to college and study even MORE grammar and when they are 40 years old say, “I took Spanish for four years in high school and I can’t say a word.”
Don’t go down the rabbit hole.
And here’s a zinger that will trigger many: TPRS has devolved into a kind of CI rabbit hole.