Many companies do use straight-line due to its simplicity and the belief that the assets are used uniformly over the useful lives. But under what circumstances might straight-line not be appropriate to use (excluding any tax purposes)?
If you are acquiring an asset that is not going to be economically powerful in recent years, but is right now, like a new technological innovation. They will be made ll the time, and certain one will lose their value rather quickly when competing on the market. In those cases, you will want to try a different method, more immediate in units of production rather than straight line. But this is just based off of my limited knowledge about finance. So if you really want a good answer, I'd recommend doing a lot of research on the different ways of calculating depreciation.