Love took to Facebook to criticise the recent performance, reported New York Post.
Many people suggested McCartney was filling in for the late Cobain as part of a Nirvana reunion. Some critics were not too happy to see the Beatle playing with Cobain's ex-bandmates on the Madison Square Garden stage.
Love said she was "not amused" by McCartney's involvement.
"Look, if John Lennon were alive, it would be cool," she added.
During the show, McCartney took the lead for a new song called "Cut Me Some Slack".
Love also said that she was upset with Nirvana members Dave Grohl and Krist Novoselic calling the performance a "reunion" because she says that Cobain was the heart and soul of the band.