It really depends on the person, situation, and if the person knows you stutter or not and how often they do it. If it's once or twice that's fine. People even do that to other people who don't stutter. Or if it's a crowded bar and the bartender is busy, then I'm a bit thankful that they can surmise what I want. But if you're just having a conversation with someone where time is not of importance then yeah, more than once or twice can be dispiriting and irritating. If it's someone you're going to be conversing with again, weigh whether or not it's worth it to talk to them about it. If it's a one-off interaction, like a bank teller or something, then I'd just leave it be.