The alternative is to try to call them "dual module" processors, and then go through a big long explanation to customers who really don't care what "module" actually is.
Can it execute two separate threads simultaneously? Yes. At full performance? Mostly, although with a shared frontend, when both units are running at full load, instruction disp---- Is someone trying to make a practical judgement of a chip's performance based solely on its core count going to have a clue what any of that means? No. Then it's a four-core processor.