My own personal rule-of-thumb is that if the place is on-trail and popular trails to begin with, I will share logistics.
But, as I found out the hard way, even if something is on-trail, people don't necessarily string together what seems obvious on a map. Once you lay out a route with the trails to take, you immediately make it accessible for the vast majority. A light bulb goes off for people and everything is easy: Take this map, take this trail, park here. Most people don't like to string together their own route.
I honestly love sharing. People ask me "What's a good hike in Colorado?" and I am happy to share.
It is generally how I operate: Share the food on my table generously. Do the little bit extra to help out. Share knowledge of what I love.
But, as I am finding out, when I innocently share what I love, perhaps I am ruining a small part of it? :)
I think there is a balance. After all, someone shared with my the route I took on my first backpacking trip. It was something he found out about through the local chapter of the Appalachian Mtn Club. That trip started a love for the outdoors that has never gone away.
On the other hand, perhaps it is best to give a sketch only. Not to give all the fine details?
I think it is great to share. I also think it is good to keep the wild places wild.
What is the balance? I sure as hell don't know. :)