Many took to social media site Twitter to condemn the comments that came just days after immigration controls were lifted on Romanians and Bulgarians entering the country.
The ITV commentary team were also slated for the fact they failed to inform viewers that Arsenal were in fact down to 10 men for the final 15 minutes.
As the England forward left the field he was attacked by a number of missiles hurled from the visiting Spurs fans, to which he retaliated by issuing a '2-0' gesture.
Walcott had been instrumental in Arsenal's domination of Spurs, as goals from Santi Cazorla and Tomas Rosicky booked Arsenal a place in the fourth round.
The draw for the fourth round will be held on Sunday.