Personally, I'd have made it a diglyph of some sort, like :* or ^*, to make it obvious to someone looking at python math code for the first time that this is a multiplication operator. @ just leaves a weird taste here.
> APL apparently used +.× , which by combining a multi-character token, confusing attribute-access-like . syntax, and a unicode character, ranks somewhere below U+2603 SNOWMAN on our candidate list.
and then later, one of the reasons @ is better than the alternatives:
OCaml has
* for int multiplication and * . for float multiplication.
you cannot overload but you can define your own,
so people tend to do things like define *: for complex multiplication.
