That's what some golf experts (real and imagined) would have you believe, including Nick Faldo and Johnny Miller, both of whom have criticized McIlroy for switching clubs. But Curtis Strange is having none of it.
Now, Strange happens to be paid by Nike, too, just like Rory (which Strange rightfully points out himself). But when he's right, he's right. And everything Strange says here (comments he made to a Reuters reporter during the Valero Texas Open) is right:
"I don't think clubs have anything to do with it at all," the American told Reuters in an interview. "I'll qualify that by saying I'm also a paid endorser of Nike like Rory but beyond that... switching clubs is no big thing.
"I switched three or four times in my career and it took me a day to get used to them, it's all overblown. I think all the top clubs are virtually identical.
"They might look a little different but the golf club is basically a stick with a handle on the end.
"Faldo and Miller have been somewhat critical of it - they are so out of line, so out of touch with club manufacturers now," said the 58-year-old Strange.
"All the clubs these days are top line, top shelf, perfectly fitted for each player. Faldo and Miller caused a stir when there was no reason to."
If Faldo and Miller believe they would have had issues switching clubs, that says more about them - and the state of golf equipment in 1980 - than it does about McIlroy or Nike.