We have about the same differences between commercial banking and investment banking, and there are many economists arguing about the need to separate (or unite) these 2 activities. We shall have the same discussion with cryptos exchanges.
Many legislators around the world are talking about regulating exchanges, this is what they should talk about first.
All big centralized exchange in the market has this two quality so they fall into the category of be regulated. It would be great if we can separate this two types of exchange just as you said because they are tempting to newbies to us when combined. It's because the options of margin and future trading are available to everyone that's why we're having individuals losing money on this type of trading that they're not familiar with.
Those known commercial exchange should stop allowing traders without any experience or proof to show that they're professional traders before they start trading using their exchange. If regulations comes then that should be one of the things they should be looking into to protect traders.