It's honestly amazing that Excel hasn't fixed this issue. It's pisses off an enormous number of users especially in basically any non-US country (even if 01/02 is a date, it isn't the second of January in most of the world...)
That's because it's not an issue at all. It's people using a tool without knowing said tool. You can disable auto-formatting (or even better yet - set the column data type) with a simple click.
The result is a rich deep program that users can grow into, rather than a shallow trivial program that optimizes for the noob experience and leaves power users out in the cold.