This is the real key. They have an awful reputation amongst technical people (for good reason) but that reputation largely fades away the less technical you are. The average person knows them for their effective marketing, seemingly low prices, and seemingly decent products. They don't get into the weeds enough to expose how untrue those things really are.

For a long time, I worked in an office across from their (now former) headquarters in the Scottsdale Air Park. The number of clients we had come in amazed that we must work so closely with them and expecting great things made the location of the office so invaluable that when they moved to Tempe and Chandler, we had to seriously discuss internally if we needed to follow them.

Squarespace is not 'tagged' in my brain under the "domain registrar" category yet. When I blindly think of domain registrars, as much as I dislike them, Godaddy is the first to come to mind.

Squarespace positions themselves as a website builder more than a registrar. In fact, I doubt the average person would even realize they are a registrar, since that is abstracted away in the website building process.