Breaking default browser behavior because you find it unintuitive is generally a bad idea.
Now if you’re dealing with something that isn’t really a web form—as in you’re overloading input fields for some interactive non form like behavior—then I can see it.
In my case, if the person had some well thought out reason for doing it, I might let it slide. But the vast majority of times I’ve seen it, it’s because the person doesn’t even know how to use forms. Not understanding the underlying technology at at least a very basic level is a strike against you in my book.