No! He was not a sectarian. No student of the Quran can be. We should call ourselves Muslims, the name given to us by Allah (22:78).
Allama Iqbal said:
AEY KE TU NASHANAASI KHAFI RA AZ JALI HUSHYAAR BAASH
AEY GIRAFTAAR-E-ABUBAKR-O-ALI HUSHYAAR BAASH (O you captive of Abu Bakr & Ali, Wake up!)
On Allama's behalf, his close friend and student, "Maulana" Zafar Ali Khan said:
HEIN KIRNAIN AIK HI MASH'AL KI BU BAKR-O-UMAR-USMAN-O-ALI
HUM MARTABA HEIN YARAAN-E-NABI KUCH FARQ NAHIN IN CHAARON MEIN (All these four friends of Nabi (S) are equal in degree. There is no difference in them.)