Because they resided in an environment that was detrimental to their preservation....improper storage will yield such results, and as such, your's ain't that bad. Welcome to the forum.........
I can still see some of the regular color on the other side but can barely see any copper or zinc on the rim.
Looks like it may have spent some time in the ground. Quite possible somebody dug that one up while metal detecting! It doesn't take clad quarters long to change color while in the ground.... I find recently minted clad quarters with my detector that have already turned colors. Most of them aren't very attractive though!
You and many other collectors are going to see alot more.. I Just dumped like 2000+ Environmentaly Damaged Quarters into a Coinstar machine! 8 years worth of Metal Detecting quarters.
lol and I was going to joke Paddyman was cashing in his reserves!! HE IS !!! @paddyman98 is going to be put in charge of responding to all Environmentally Damaged coins from now on ...