Use proprietary technology isn't the problem by self. Teach at schools proprietary technologies as the only way to learn is the real problem.
In my country (Spain) Tech Enterprises uses schools like academies to perpetuate their products and the result is monopolies and the end, monopoly=abuse
Teach at public schools, for example, only "cisco IOS" or "CDP" is good for Cisco, but is bad for kids and other rival companies. Kids grow-up, finds jobs in companies and buy tools and tech to work. What company has better position to sold their products? Right! Cisco. You Know.
In your example. The problem isn't USE ink-pens with proprietary tech.The real problem is TEACH that the only way to learn is using ink-pens and hide the existence of pencils.
Spain public education is a disaster (80% of people or more goes to public education). Few government investments. Teachers don't have recyclables courses to be up-to-date, and IT tech are always moving so fast. Companies knows this problem and tries to get profit for this situation.
Simulators are tools right. But proprietary simulators aren't neutrals. They are always telling you if you uses my proprietary protocol you will have better solution less problems, etc.
Actually in Spain the big problem in tech education isn't Cisco. Would be, but we have a biggest problem and is called Microsoft. ;-)