Yes, regulations around security tokens are strict. If you realized, Dreamr is the first security token to hold an STEO (Security Token Exchange Offering). There must have been some complications which led to the token sale being moved to their website or it might be a move to draw traffic to the website too.
Traffic doesnt mean nothing to Dreamr platform. Its wont be used by google for advertising. I think the reason token sales was moved to the website was because they wanted to ensure that only Non US investors purchase the tokens. Like you said, these are a different type of cryptocurrency, and strict rules have to be followed.
It's possible that the major reason for the movement to the website is to ensure that only non USA citizens invest in the project. But are you trying to say that the kyc procedure of IDCM exchange is not sufficient to distinguish between citizens of USA and non citizens? I know that dreamr intends using a third party company for the kyc on the website and that's not really different from what we have in IDCM exchange.