More specifically, it’s a CSS element that can be edited to your hearts content. The reasoning for the “hide” show is if you’re running multiple tasks, the page would not only be long with it always expanded, but it would also be confusing, potentially, for users to know what host the progress bar is actually for.
The other issue I see with making this fully expanded is the requests to get it hidden. Is it really that hard to hover over it? I understand the timeout re-hides it which I can look into, but I find the “minimized” bar a good way to see on the fly tracking. I may not know the exact percentage as that’s hidden, but I can still get a rough estimate of how far along the item is.