If you read the ET EULA, you will find that what sort of mods you are allowed to create, and what you are allowed to do with them is quite restricted. In particular, you are very clearly not allowed to sell them. Note that most ‘hacks’ don’t involve scripting either.
There are also ways you can speedhack by making your CPU do work faster then its intended to. (Basically change some clocking settings. Lets say you shot 100 rounds per min normal, once you speed it up 10% your shooting 110 RPM. Its such a small ammount no one will notice, and it will give you that extra edge.
FWIW, that description isn’t really correct, and generic speedhacks don’t work in ET.
And a hacker is really a well versed computer programmer.
You are confusing (or deliberately conflating) two different definitions of the same word. The people who create aimbots and wallhacks are not all skilled (although some are), and having such people exist certainly isn’t responsible for the existence of ET.

