I must agree with you, your brother in law must have done the best and right thing for his situation. As all applications are case to case basis. Only a person, has the right to pick the kind of pathway most suitable for him/her with no questions ask. I should say too that caregiver pathway and other pathways have its own battles, if you are not physically and mentally prepared it will be more challenging. Caregivers are intelligent too and professionals, not to mention probably nurses or teachers who chose this pathway that might contribute to related-work experince for latter plans.
I believe this forum is made to strengthen one another and contribute to the positivity. We are all facing the same predicaments, lifting one another is rather helpful. The reality is given, let us support one another.
Kudos to you Twinkleberry and to everyone who is keeping their faith to the strongest.