John Deere does not make ATVs, they don't make any tier of people moving equipment. The idea that they should use their own is ridiculous. If they didn't enforce the Honda rule, people would be riding around in the front of dozers.
Much in the same way that if Stanford invented new bulbs, they would be used in a lab. With safety standards applied. Why don't you want these newly invented bulbs used all over your building? Well, what happens when they burn your building down? What happens if the people in the lab who invented them decide to make a company selling them, and are busy with that, and now you need to pay your maintenance people to deal with these new bulbs they don't know how to use.
Being slow to change in a larger organization is a feature, not a bug.