I got scolded by a shop owner while paying for something!!

‌I was out on a business trip in a quiet rural area
To quench my thirst, I went to a supermarket and tried to pay
3,200 won for a canned drink with my card, but the owner said,
"If you're going to use a card, buy more than 10,000 won. There's no profit in this,"
and scolded me.
It was so absurd,, I did something wrong, right?
I just smiled and said, "I'll carry cash from now on," and walked out
ㅋㅋㅋㅋ damn it