The answer is many-fold.
The first is that I simply like foxes. The are cunning, resourceful, and adaptable; having spread to every continent on this little green dirtball with the exception of Antarctica -- and if you wait until they get the plotting and logistics done probably that frozen hell, too.
They are efficient hunters, surprisingly good fighters; and are featured in many mythos -- usually as a Trickster figure.
What really endeared them to me was watching a mated couple outside the barracks at Aberdeen Proving Grounds. Every evening the male would come trotting back to the den with a mouthful of dead rodents -- very much with the air of a guy in a red flannel suit heading home after an exhausting day at the office -- where he'd be greeted with a nuzzle by the lady of the den, and they'd feed the pups.
Something about that contented domesticity during a very chaotic period of my life sang to me.
Years later a friend bought a carved soapstone fox totem and gave it to me, and for years I carried that little carving, or others that my mother found, to remind me to be adaptable; that cunning (done properly) was usually better than force; and that when it came down to fighting, to be sneaky, vicious, and unpredictable.
It doesn't hurt, I suppose, that I am a red-headed, slender-framed male of average height, as far as the fox comparisons go.
However, the biggest reason for the fox memes is that Facebork is one of the levels of Social Media Hell, and making fox memes keeps me out of trouble with Zuckerborg and his legion of easily-offended uber-minions.
This has been your Monday what-the-hell-am-I-gonna-post edition. Have another fox: