They work no better than bird wings, AFAIK. So what's the point? You need to give one rational reason other than "God felt like it."
If God loves wings so much, why not create a different wing type for each bird?
Why. When I draw a picture or sculpt someone, I don't need a rhyme or reason. I do what the heck takes my fancy to do. I don't sit back and worry myself about being subjected to an inquisition by you. Why should God have done so. Did he have something to fear from your disapproval of how he did things. Again, awful presumptuous. Has it ocurred to you that the way Bats hang upside down in wet caves and hold their young might present problems if Bats had feathered wings. Bats don't act or function like birds. And if efficiency of design is such a no brainer and Lamborghinis are the best car on the road.. why aren't semi trucks shaped like Lamborghinis. Oh, that isn't fair is it. screwing with the design of something obviously meant to serve a different purpose and operate differently. The design makes sense for the purpose of the critter. But who knows - if I can see that - perhaps a mighty being capable of speaking the sun into existance can also design a bat to function properly.. Might be assuming too much for someone whos ways are much higher and more complex than ours.