Javascript is a prototype based language and "this" is a stepping stone. Creating new objects inherit from prototype methods with "this" pointing to the instance, or it is different to call a function directly or call it via a reference from an object. Many built-in javascript functions such as map, reduce, forEach, some, every ...etc will except an optional argument that allocates value to "this".
These can make your life much easier. I do understand people who tend to not like it. And if they do not want to use it, sure they can.