Would it be better if it was a platform only token, rather than on exchanges at all? I have no idea if it can be taken off exchanges.
Also, wouldn't it work better to have a second layer token act as the stable coin, instead of one integrated into the blockchain itself?
Could be advantages to a second layer token, but also disadvantages. One being HDB is extremely simple at the blockchain level. The risks of errors in complicated smart contracts are significant in practice. I'd be more comfortable holding something like HBD than any complicated second layer token that isn't extremely well audited and proven out (DAI, itself, is probably okay, but many others trying to do this are likely not).
I don't see any advantage to not being on exchanges, nor can you prevent it. Just have to deal with it.