I agree with many of your criticisms (made a few of the same in another comment), but you missed a few points in their favor; looks like you spent a lot of time on this rant, it would have been good to spend a few minutes reading their FAQ and watching their video to make sure your criticism were valid.
Adding a card seems flawed. You're asked to take a picture
of the physical card after swiping to "prevent fraud" ok
but unless Coin uses some advanced image processing/OCR to
validate the card with the swiped data, you can take a
picture of any card. So big fail here.
Why do you expect them not to do image processing and OCR? Credit cards have standardized, highly OCR-able fonts. I would be very surprised if they didn't OCR it.
Most users are totally fine with credit cards and big
wallets.
I'll have to disagree with that. There may be a few people out there who appreciate the physicality of the cards, but based on personal experience, I'll bet a lot more would love to streamline it. In fact, I would love to not carry a wallet at all, just maybe a billfold and a single card or my phone. The problem is this doesn't go far enough; it only eliminates a few cards from the wallet, it does nothing about all of the health insurance cards, rewards cards, drivers license, membership cards, subway cards, etc that clutter people's wallets.
The obvious issue of losing Coin and losing everything.
People like backups. It's a mindset.
According to their video and FAQ, the cards are backed up to your phone. If you lose it, you can just get a new one and transfer your cards to that. And your phone will warn you when you lose it. Actually, one of the big draws are those two features together. Much less anxiety about leaving your card behind.
Battery issues with digitizing a non-battery product
(credit card).
They explicitly state that the battery is non-chargeable and non-replaceable. You don't charge it. According to their usage model (which includes much heavier usage than I use any of my cards, I generally use a card once or twice a day, maybe 4 or 5 times on a weekend), it will get two years life.
While I share the same concerns about privacy, compliance, card not present, and so on, I feel like you went out of your way to pick out problems, ignoring several things that were obvious from their FAQ.