And you are most certainly wrong about that.
Now, apparently Australia does require visas of US citizens. But there is an ETA for 20 aussie dollars (Electronic Tranist Authority) so it's not technically a visa stamp in the passport but close enough.
Although it may be technically incorrect to do so,I'm using the word "visa" to be roughly synonymous with the phrase "leave to enter".
For example....in most cases a US citizen wishing to visit the United Kingdom for the purposes of tourism for,say,two weeks doesn't need to have anything stamped in his passport saying he has permission to enter the UK when he leaves the US.The same,I believe,is true of UK citizens wishing to enter the US under the same circumstances.*However*,if that foreign national arrives at an immigration checkpoint in,say,New York or London and is deemed by the Immigration Officer to be "unfit" to enter,that foreign national *will* be denied entry and placed on the next flight to the country where his trip originated (I know...it almost happened to me in South Africa).
So,anyone who might suggest that Snoop Dogg might have some kind of inalienable right to enter Australia (and I don't know if *you* did so) is absolutely incorrect...regardless of what stamp Mr Dogg may or may not have in his passport.