Because it is a cheap substitute that has greatly reduced amounts of Nickel and uses High amounts of Manganese (cheaper than Nickel) to try to stabilize the austenite.
Also very high levels of Nitrogen and sometimes Copper is added too.
If the application is limited to atmospheric and "kitchen" corrosion potential, it might be a choice based strictly on price. On performance and in any environment where intergranular corrosion is a threat, it is unsuitable.
Cheapest does not equal best, whether in tires or toothpaste from China or stainless steels designed to be cheapest not best Corrosion resistance.
Caveat Emptor.
Personally I can't imagine a situation where I'd recommend it. price issues or not.
BTW- mechanical properties are considerably different than say 304. look at yield strength.
milo
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People say between two opposed opinions the truth lies in the middle. Not at all! Between them lies the problem, what is unseeable,eternally active life, contemplated in repose. Goethe