There's no reason they don't. People who don't understand it or don't want it can use the default event system, people who want to use it can install the add-on. It's funny, because using a more complex system is easier than the current system. If you just want to make a door that disappears and such then the events system is perfect. But as you get closer to making more complex things, the simplicity of the current system bites you in the ass because it becomes much more complicated to make functioning things, such as a computer. VCE and the like might make it easier, but it comes back to the current system being good for simple things but harder to navigate and make larger event projects.
M's comments imply that the two systems could not coexist, thus user choice isn't a fair excuse for creating such a system.
My two many problems with the idea are:
- It will raise the barrier to entry for players
- It is an unnecessary complication
The first problem involves two barriers that will harm new and existing users; GUI(s) will be required to participate in the server and it will have a steeper learning curve than the existing system. It inconveniences and alienates players for minimal gain.
Why is it an unnecessary complication? Because you're trying to use eventing to accomplish what would be better served by a script made outside of the game. I don't think eventing was ever intended to be used to produce RPGs or to simulate computers. In doing so, you're being impractical for the sake of impressing people.
Gmod's
Wiremod is a perfect example of the risks of implementing such an idea. It opened up a whole new way to build contraptions that the creator never envisioned, but it divided the community; it resulted in a pseudo-class-structure of those who knew how to use "Wire" and those that don't. It puts an incredible burden on players to find, download, and install the latest version of the mod lest they miss out on participating in the most active servers. Worse still, creations made using the basic tools of the default game are looked down upon as being primitive and unworthy of praise. New levels of absurdity have been achieved as now the "best" creations are made through some scripting language that then operates through components placed in-game; they have come full circle! And to what end?
My point is this: Yes, users may
chose whether they download and use the suggested system but, given the pressures that would result from it being prevalent, they would only have the illusion of choice.