I'm a huge Tesla fan but I have to admit that the Tesla doesn't seem great for such a road trip. 15 hours instead of 9 is a big deal. Of course most Tesla owners keep a gasoline car too. So everyone already knew that.
However, if you're wiling to do a bit of your own thinking and the supercharger network accommodates your trip well (which it mostly will at this point, there are some holes but most people won't have trouble), the Tesla is a fantastic road trip vehicle. It's quiet, smooth, and comfortable, which means you won't be as fatigued. Superchargers are located at convenient locations so you can get a snack or a meal while you charge. My experience so far is limited, but range anxiety for me has been less, not more, because I know in advance exactly where I'm going to stop, rather than trying to search for a gas station in just the right spot, trying to find a cheaper price, etc. And of course paying $0 and not being bombarded with carcinogens is a big bonus.
I don't know if most Tesla owners keep a gas car. I didn't, and not keeping one seems pretty common. Unless you plan to take trips into the relatively few supercharging deserts, you really don't need it.
What the article talks about is 100% expected due to the target market of the Tesla and the current state (still building infrastructure) of the charging stations.
There are some destinations which are inconvenient right now, but most road trips can be done easily. Much of the trouble the author had was avoidable with a bit more forethought.
Early adopters have early adopter difficulties. This article is a no-op.