Because they were good for the customer rather than the advertiser, and the money to Apple came from the advertiser in this case.
For example roaming the city at 4am on a Saturday and trying to find some place with hot food. Google failed miserably at this. Eventually I found something but just because I knew it was often open at night. It was also marked open on Google Maps but never came up in searches there. Probably other places paid Google more for a listing despite being closed at that time.
Not sure how Apple does with this as I don't have any Apple anymore except a work iPad. It's too limited for me in terms of what I can install. But there's certainly some room for improvement in mapping.