JWs say: we are Jehovah's Witnesses, not we are Christians or even Jehovah's Christian Witnesses.
JWs rarely mention at the door that they are there to talk about the Messianic kingdom (instead God's kingdom). Check the canned presentations the WTS provides...how often is Jesus mentioned.
But some non-JWs think because JWs do not celebrate Christmas and don't believe Jesus is part of a trinity, that means they are not Christians.
Blondie