I always thought stain, which soaks into the wood more than paint, was better than paint for some purposes, like high-traffic stair treads or places that get extreme weathering. No?
Depending on its opaqueness, stain can offer a certain degree of UV protection. The darker the stain, the better the protection. Stain does not provide protection against moisture or scuffing.
A clear coating like polyurethane provides protection against moisture and scuffing, but offers no UV protection.
Paint offers the best UV protection, good moisture protection, and resistance against scuffing. It has two disadvantages: 1) You may have to scrape it off (or sandblast it off) before repainting, and 2) Touchup work requires a matching color.
This I don’t understand. If stain soaks in more than paint, wouldn’t scuffing cause less damage if the surface were stained? you scuff paint, a layer scrapes off. You scuff stain, it just abrades the wood and reveals more stain deeper, at least to a point. Is this what actually happens, or am I way off the mark?
With hardwood, stain does not penetrate very far; it is easy to “remove” the stain with a little bit of sanding. (I’ve done it many times.) Scuffing will often remove a top layer of the wood, revealing the unstained wood underneath.
With softwood it’s pretty much the same story; the stain won’t penetrate too far due to the wood conditioner that was applied beforehand. And keep in mind that softwood (with no clear coat) will scuff easier than hardwood.
The bottom line is that, for the best outdoor protection, wood should be *painted *with a high quality, outdoor-rated paint. (Here’s what I use. It’s not cheap, but it’s the best, IMO).
And because we live in a log house, I spend my summer’s cleaning and staining wood. 
I use a *dark *stain.