There are none so blind as those who will not see... I noticed you have a 'bent and living in a sunny climate, riding year 'round and having no overhead protection I made a cover for my Sun EZ. It worked like a champ. I found a fitted full sized sheet at a thrift store with a pattern that looked attractive and not budoir like, took some clothesline cord and used this as a first time sewing project making a 'pocket' for the cord and voila. Because Neddy Naysayer likely only rides DF bikes, he's not aware of a 'bent issue of sun scorching your seat back and seat cover when your bike is parked out in the open sun for 8 plus hours at a time.
Then too, Neddy Naysayer also isn't a motorcyclist who's learned how much a simple cloth cover can be a notable theft deterrent simply by being one more step a thief needs to take in order to fk with your lock and in fact, depending on your environment, can be used AS a lock, if you're brave enough by simply hiding whether or not it appears that you HAVE locked up your bike.
Good luck in your search and it isn't a silly idea as someone here wants to make it. Some folks are only able to see their perspective and unable and unwilling to consider other ways of looking at things.