Sure, you are right, it would be a waste to keep your bitcoin on exchanges when a fork it's going to happen (or even all the other time)

Coinbase even pronounced openly, that they will not offer the new coins to bitcoin owners.

However what is bitcoin cash?

In my eyes it is only a new shitcoin. There is technically no reason to keep to version of an obsolete first Generation crypto currency.

It might be like etherium classic, which has a quite big market cap with almost no technical advantage but only because it's name is related to etherium.

Therefore I fear something called bitcoin cash could remain a great market cap where it should not (especially for newcomers, who see the price of bitcoin, do not know what bitcoin plus us bur will buy it because it is a little cheaper and they hope for big money)

In my opinion it would be far better if a good 2. Gen coin (maybe Dash or IOTA?!) should gain value in order for businesses to get interested in it and accepting it for daily transactions.