I think the word you're looking for is discoverability (or perhaps visibility).
The problem with Solaris, Windows, and other desktop workstations at the time was that the second (and even third) mouse buttons were required for many workflows, especially in applications---i.e. a lot of functionality was only available from the right-click menu or via the middle mouse button. This introduced a lot of unnecessary complexity to computer use, especially for new users, because of low visibility and discoverability.
Even today, Mac hardware never has a visible 2nd mouse/trackpad button. Sure, you can click a trackpad with 2 fingers or tap on the right side of a mouse to get a context menu, but keeping the buttons invisible forced these shortcuts to remain just that, and not an essential requirement to get the job done. Windows apps today follow this rule as well -- never make right-clicking the only way to execute a particular function.
This, unfortunately, is slowly going away. The Home app in the new macOS, which has been ported over from iOS, is unusable if you don’t know how to two-finger-tap.
Discoverability is a very hard problem on the small screen. I’m amazed at how often I actually know a function exists, and I try every conceivable type of interaction I can think of to no success. Then I google it.
Damn the little tip about tapping the clock to jump is so handy, I have actually searched for how to do this and never came across a description of this feature.
The problem with Solaris, Windows, and other desktop workstations at the time was that the second (and even third) mouse buttons were required for many workflows, especially in applications---i.e. a lot of functionality was only available from the right-click menu or via the middle mouse button. This introduced a lot of unnecessary complexity to computer use, especially for new users, because of low visibility and discoverability.
Even today, Mac hardware never has a visible 2nd mouse/trackpad button. Sure, you can click a trackpad with 2 fingers or tap on the right side of a mouse to get a context menu, but keeping the buttons invisible forced these shortcuts to remain just that, and not an essential requirement to get the job done. Windows apps today follow this rule as well -- never make right-clicking the only way to execute a particular function.