I think the usage to store other type of type is getting popular very late after excel has being invented. It was created to count money. So it would make sens

I think the usage to store other type of type is getting popular very late after excel has being invented. It was created to count money. So it would make sense to defaults field to number unless it obviously isn't. People are just using a tool that isn't designed for your current purpose. I think probably the best change it can do is don't alter the data at input. Instead, alter it at display and compute. Then it won't actually corrupt your data anymore. Then for a wrong field type, you just need to change the type, and the correct data will be displayed as expected.