How fast do you think the 350 000 000 cap is reached?
tell me when, in crypto history, someone raised just half of this amount

Everyone wants in. This cap will be reached easily in the first 30 minutes. TheDAO rises half of this amount and Ethereum was like 36x cheaper back then, so in terms of ETH collected TheDAO has risen even more.
You should look at USD price, not at quantity of ETH.
..i'm saying this, but i'm going to invest in this ico, just to clarify

Most people do not look at USD price. We simply hold some amount of ETH and will invest some of it no matter if the price is X or Y. Someone decided to send 50 ETH, someone 5 and someone 500 and how it is priced that day is not that important. I think devs understand that and that's why it is capped in ETH and not in USD.