A lot of martial artist think that any changes they make to a style are good changes, unfortunately that isn't always true. Some styles have the same or similar concepts, but some styles aren't alike at all. Blending techniques that have entirely different concepts can get messy and chaotic. We all have preferences, some like kicking more than punching, others like grappling more than striking. For example; if I took tae kwon do and realized it's not for me why would I keep training it? Would it make sense for me to study for years, open my own school, replace all the kicks with boxing techniques and still call it tae kwon do? When questioned I can just say it's my "own" version of tae kwon do.
I have changed martial arts schools multiple times because I concluded it wasn't for me. It's a difficult choice to make, but in the end you'll find something better. Eventually, I found Kali which is the perfect style for me. It has everything I was looking for and more.
That's not to say you can't add to an existing style and still maintain the core concepts of that style. For example; my kali instructor has a wrestling background and we incorporate wrestling techniques into it, but it blends well with a lot of the kali techniques. However; we don't neglect or replace other important training regiments in place of the wrestling techniques.
Some Wing Chun doesn't resemble real Wing Chun at all. They "adapt" it in ways that draws away from the center line and economy of motion concepts yet they still call in Wing Chun. I have witnessed this with other styles too, but from my experience the Wing Chun community seems to be riddled with this problem.