Some ICOs apply investment limit per person, that can stop some whales from dominating the coin supply, in addition, dump might bring more holders, not bad for long term vision.
And how do you think they are going to regulate the users? It is quite simple to spoof your ID or your location or your IP. Just a matter of time and even simpletons knows how to do that. The can make multiple IDs and invest more. So it's the same thing.
ICO token companies can enforce a a rule such as not dumping all of them. They should be enforce limit dumping in that way the crash does not happen all of a sudden. Limit dumping putting 10 % per day dump like stocks so retail guys like me would not get hurt with all our savings gone.
Steemit actually has something like that, where you can't withdraw all your coins and dump it. You can only withdraw a percentage of your coins overtime. Same thing can be implemented in ICOs.