You've gotten a lot of great replies, but I wanted to add - Because doctors are in a position of authority and knowledge, it's hard to go against what they say. But sadly, lots of doctors give unrequested PARENTING advice rather than just sticking to MEDICAL advice. And obviously, people differ a lot on their parenting styles/beliefs.
As your child's most important advocate, you've just got to sift through the opinions vs. the medical facts (and, of course, it's good to read info from AP-supporting doctors).
I had 3 doctors tell me to let dd cry it out, but they all suggested different ages for different reasons. (Like, "you absolutely HAVE to do it by 1 year, because by then they're walking and harder to contain." Or, "If you wait until older than 18 months, it's way harder because she can talk and it'll be heartbreaking to hear her cry for you." etc. etc) And they even suggested even though she had reflux, when crying greatly exacerbates reflux!
Now, of course, if you get to the point where you're unhappy with nursing to sleep, then you can work out a gentle way to transition from that. But let it be YOUR choice, not the doctor's.
Keep up the good work, mama!