ICOs should not control how much they need to raise, otherwise they would have to limit the amount and create potential 5 minute ICO madness that is profitable only for the first few investors who managed to push transaction through congested network during first 5 minutes.

Dan created at least 3 good things: BitShares, Steem and fair ICO, so he gets his billions for his past results and good ideas. It's not his fault that investors push billions into his pockets. However I agree with you that BitShares suffers from lack of needed improvements due to Dan jumping on something else, like there is no bitETH market pegged asset, which would greatly improve exchange volume. Without all market pegged assets for all popular crypto currencies there is no difference between BitShares DEX and Poloniex in terms of 3rd party trust risk.
I don't like how BitShares DEX is half finished, but I guess BTS voters decided to not pay him to finish. I also wonder if anyone did reliable measurement of BTS speed or tried to spam the network like ETH or NXT to push it to it's limits and see if it goes down.
Latest news about Poloniex disabling BTS wallets does not add trust towards BTS.
His selection of hosting ICO on ETH instead of BTS is cool because he does not have to sell invested BTS putting pressure on his past creation BTS. Instead he will put sell pressure on ETH, which shows loyalty to his past investors.
The only fair way to control/limit total investment amount is to proportionally refund invested funds at the end of the ICO to make total valuation amount not worth more than X millions of USD or X thousands of ETH.
That way he can give proportional advantage to whales without taking from them insane amount of funds.