I'm sorry, but I see two things wrong with that.
1) If you make lying (bullshitting) a part of everyday work, you're going to run into problems. At least, I would, because whenever I speak I'm always straight-forward, sometimes even blunt. It's just the natural thing for me. If I'm concentrating on the problem I'm trying to fix, I can't afford any brain power to put towards faking I have people skills, so instead I just be myself. For many people, "being yourself" works great because it's natural for them to chit-chat with people. It's not that way with me. The natural thing for me to do is keep silent and do my job. If the user initiates a playful conversation, sure, I'll play along. I won't start one myself though. And I'd think the only users who would see my silence as anti-friendly would be those who are into the chit-chat thing, which means they would've started a conversation themselves anyway. And those who wouldn't start the conversation themselves also wouldn't see my silence as anti-friendly. So, it makes me wonder, what kind of person brought this up with my manager?
2) In this job, being too friendly can actually backfire. The users are supposed to call the helpdesk when they have a computer problem. The helpdesk triest to solve the problem over the phone, but if they can't, they fire a ticket off into my queue so I'll go help the user in person. But just think - what if the users's experience with me was much more positive than their experience with the helpdesk on the phone. Do you think they'll ever call the helpdesk again? Hell no, they'll just walk up to me because I'm nicer and make them feel better. We have enough of a problem with walk-ups as it is.
I know my communication skills aren't that great, and I wish I could improve them. But I think it really just comes down to personality. The people who do really good at a job like this, dealing with users, are the people to whom it comes naturally to make friendly conversation all the time. They don't even need to think about it. They can put all their effort into solving the problem and let the people skills take care of themselves. My colleague Mike is like that. I'm not. I have to think about every action I take, because it won't happen on its own. It's not a part of my personality.
And you can't change your personality. You can't change who you are.