The 39-year-old won his 13th league title with the club on Monday following the 3-0 win over Aston Villa at Old Trafford.
"That is beautiful. I like the people that fight for their colours and don't change [clubs] every two months to make business," Platini said.
"He's a guy who would never change clubs."
Platini, a former France captain, says Giggs's loyalty is to be admired.
"To make business you have to change clubs often. It's a pity we change, change, change but I know why we change.
"It's not because to be at better clubs, it's to have better money.
"Ryan Giggs is totally different. It's important to create an identity and it's important that one guy for one club fights for the colours."