For many years I tried to convince myself that a shul may actually be friendly if the Gabbai came up to me to say good Shabbos and then asked me if I was a cohen or a levi before retreating back to his perch atop the bimah, but I have come to the conclusion that it was wishful thinking.
A shul’s friendliness or lack thereof should never be judged by the gabbai or anyone else that says welcomes you for ulterior motives than the genuine friendliness that should be endowed upon anyone entering a place of worship. You have undoubtedly realized that I wish all shuls were endowed with a friendly atmosphere although I understand that this is not possible for many, New Yorkers for instance have been ingrained with a nasty attitude that cannot be changed unless they move very far away or attend a hashkama Kiddush club.
Attitude runs deep and although the person who just offered you their hand and welcomes you to the shul, they may be wondering whether or not you are eligible for an aliyah, able to lift the Torah for hagbah (you can judge by the firmness of the handshake) or wealthy enough to make a donation after receiving that post aliyah mi-shebarach. If they give you an aliayh is should not reflect positively on their friendliness factor – they may just be using you.