A social myth drives statements like the one your coworker made. The myth stems from ignorance about diabetes. Many people believe that T1D is the "bad" kind of diabetes. T2D comprises the overwhelming majority of diabetes.
The social beliefs related to T2D often color beliefs about T1D, whether accurate or not. Many T2Ds see insulin use as a mark of failure (it's absolutely not!) and they conclude that since all T1Ds must take insulin for the rest of their lives to survive, that they have the "bad" form of diabetes. I also think that the emotional trauma surrounding the fact that many (not all!) T1Ds are diagnosed as young children creates a special worry and uneasiness.
I believe that T1D generally demands more moment-to-moment active management. Having said that, I'm very aware of the extensive management efforts of some T2Ds, as well as their amazing control! Using insulin, whether for T1 or T2, makes one more susceptible to hypoglycemia but it's also a highly effective tool to control BGs.
I know how you feel about the social misperception your coworker suffers. The only way to neutralize that is with communication of actual facts. Unfortunately, we must deal with this on a one-to-one basis. I don't think we will ever live in a society where this does not occur. I think it's part of the human condition.
Since this tapped into an emotional sore spot for you, consider this an opportunity to engage in an effective antidote. Talk to your coworker and dispel some ignorance. It will make you feel better. By the way, congratulations on your excellent A1c and BG control!