What was the quality issue here?

When I open your photo in Photoshop, I can't see any camera data. Are you shooting raw, what corrections are you making? The one thing not clear to me is if you over sharpened the photo.  Moderators sometimes reject photos for “quality issues”, when they shouldn't.  When I am certain the image is a good, I make a minor adjustment and resubmit a couple of days later. Most of the time it gets approved the second time. Just darken a bit and add a little saturation (just a little).

I believe this is a good marketable image, and deserves another chance. 

Too many images already exist in all categories, if I thought about that before I shot, I WOULD NOT be shooting stock. I just can not comprehend why so many people obsess with that.

Slow down and be intuitive when you shoot.

Best to you! 

Comes across as a touch overexposed to me. Try adjusting exposure, then re-open the shadows. But maybe not quite as much as I did in this example. This version might be a bit on the dark side.

Hey ​@natureloving_naturalist 

This is cool image. 
One thing you may want to consider. Create a frame of a sort using the wood and clean up the image a tad bit to remove any distractions or things that would be poking you in the eye. 

There are already a large number of entries using the keyword "firewood."

This may be why the review process has become stricter.

I recommend carefully considering the theme when taking your photos.

You can crop and resubmit however, I feel that sharpening is needed and the WB or color needs adjustment.