How taboo is it to switch up beers at a bar?

[pshreck]

I've only been 21 for about 8 months, but have been going to bars for those 8 months more than frequently.

I've noticed that it seems weird to change beer orders in the middle of the night. A few times I have been at an Irish pint night (2 bucks for Irish draughts), and have switched from Guinness to Smithwicks about 5 drinks in, and the bartender looked at me confused when I didnt stick with my first few drinks.

A few other times I switched from bud light to Coors light. In cases like those, it has nothing to do with taste, just I occasionally like to mix things up.

So... my friend asks me why I often switch up beer drinks, and I have no good answer. I have to agree with him though, no one else ever seems to do it, and bartenders seem to be miffed by it.

I just went to Montreal and only ordered Labatts for about 4 days, and it was great.

So.... why is it so weird to switch up beer orders?