A dotted blue path indicates a path to walk on. This shows up in public transit or walking directions where part of the trip actually involves walking.
A dashed grey arc appears when Google Maps can't actually get you all the way to the destination but can get you close. This arc indicates distance, but not a particular route. This is what the screenshot in the article shows (except the screenshot shows light blue instead of grey for some reason).
In particular note how the arc in the screenshot is perfectly smooth instead of following a path, a lighter color than the rest of the route, and dashed instead of dotted.
"It wouldn't be outrageous to assume that Google will automatically switch from driving to walking mode at the best location to exit your vehicle."
On the other hand, it also wouldn't be outrageous to assume that if an app is giving you "walking directions" that the route would be walkable for an average user rather than "highly dangerous, even for experienced climbers".
Sure, I think that would also be a reasonable guess, without a warning. Both are reasonable things for someone to think a company that shields itself in a cloak of magic were to do.
Honestly I stopped using USGS maps for moderate hiking and just started using google topo maps because they show trails, I'm not going to assume anything about a trail though just because google says it'll get me from point A to point B. I also actually know how to read a topo map so I know the kinds of things to look out for.
My point is that Google maps pitches itself as amazingly clever about giving directions. Expecting it to suggest when to change modes of transportation is totally within the realms of what Google certainly is capable of doing; they used to do that for that meme where they say to drive to some location in New Jersey and then swim the Atlantic to get to France. It still said where to start swimming from and where to dry off. And that was like 15 years ago.
Calling out warnings for dangerous trails like they do for traffic jams seems like an obvious thing to do for both situations, just do the same for when it's not actually suggesting a path at all. That'd be great!
I've been misled a number of times by Google Maps driving directions to places that can only be ultimately reached on foot, because in general it tends to route to the nearest drivable location by straight line distance and not necessarily the starting point of a usable/preferred walking route. Which seems to be what happened here. I don't usually attempt walking regardless, though!
Almost worse is that there is a walking path from the car directions end point to the top but it’s a difficult trail suggested only for “experienced hikers.”
A dotted blue path indicates a path to walk on. This shows up in public transit or walking directions where part of the trip actually involves walking.
A dashed grey arc appears when Google Maps can't actually get you all the way to the destination but can get you close. This arc indicates distance, but not a particular route. This is what the screenshot in the article shows (except the screenshot shows light blue instead of grey for some reason).
In particular note how the arc in the screenshot is perfectly smooth instead of following a path, a lighter color than the rest of the route, and dashed instead of dotted.