I fully agree with that. No exchange or any program or establishment can be perfect, so the best ones could disappoint you when you need them most. If not the technical failure that you emphasised in this thread, it could be some other poor service or manipulations.

I've caught exchanges manipulating the market price just because they want to "bucket chop" the trader, which is off. They hunt stop losses too. So if you divide the money in exchanges and one disappoints you, the other might still save the day.

Lastly, those whose accounts were frozen didn't expect it. Even if the account is later unblocked, what about the many times wasted? We have many more reasons why our exchanges shouldn't be limited to just one.