I own plenty of domains where the traffic bleeds over, and that's not all that bleeds over as well...
I don't give present internet users any credit, because I have run websites that dealt with hundreds of transactions ever day... and if people can mess it up they will... repeatedly.
The problem isn't navigating, it's remembering.
We are beat over the head with .COM over and over, my kids under 6 only know .COM and they live in the gTLD age. Most teens right now only know .COM and .NET, and only that it exists - I have a few in my family unit, and I often ask them internet questions to gauge what their awareness & experience of the internet is.
Most of them only know Apps, so if anything that is still the largest danger to Domains - if at all. Apps still need domains to run and promote. Snapchat just sealed a deal with Viacom to kick up their advertising so that they can reach a larger demographic.
I frequently use a site that is an .eu, good luck communicating that to anyone in the United States... most people are just oblivious and will forget the extension and will try for the .com.
When someone is navigating to a domain they will almost automatically want to type .COM, because an address can be hard to remember in itself.
Once they get there, they will be met with something unfamiliar to their subject matter, and they they will either give up or go to Google (.com).
At the end of the day, this .net is for a 'throwaway' promotion. I didn't even need to go to VisionWorks (.COM) website to figure this one out. But I did...
LetsGoSee.net - "Children's Eye Health Campaign to Raise Awareness of Importance of Annual Eye Exams"
Not really an earth shattering commerce idea that warrants the high priced acquisition of a .COM.
They have enough money to launch on a .net, and if the campaign is turning significant ROI they will buy the .COM and redirect to the .NET. Oh yes indeed, a redirect to a .NET to keep brand continuity for all of their endurables created today will probably say .net on them.