One brewery, One yeast

I was at The Atlantic Brewery in Maine tonight and noticed that they only used Nottingham yeast for all their beers from summer blondes to porters to braggots.
I confirmed this with one of the staff at the bar.
I found this interesting in that they don't match specific styles with the corresponding yeast strain. Is this common with microbreweries?
I do like most of their beers. The summer ale was refreshing and tasty. My wife is the hop head here and she liked the flavors in the dou ble IPA. Their real ale was clean but a bit bland.

Each place makes their own choices.
Sometimes you lose a little of the craft for the convienience to make mass amounts.
I'm sure some might find it simpler to use one yeast only.
I know of one brewery that doesn't recirculate their mash.
I wouldn't say that it's common but then again i haven't gone from brewery to brewery asking them what yeasts they use.

All depends on what your products are, and what your yeast strain is.

Some strains can be very, very versatile. By adjusting pitching rate, aeration, wort gravity, wort composition, and then obviously fermentation temperature, you can coax a bunch of different flavors out of a number of different yeasts.

Best examples I can think of are the middle ground between English and American strains- strains that when pitched high, aerated well, and fermented cool are very, very clean, but when fermented warmer and/or stressed (underaerated or underpitched) can be quite fruity.

The divides that are harder to cross are the phenols, I'd say. Can't replicate a Belgian yeast character or a Weizen character without the correct yeast, and in correlation can't use one of those yeasts for English/American styles or Lagers.

So I guess the point is again what you're trying to do. If you're brewing only a certain family of beers, you could absolutely get away with only using one yeast.

Many commercial breweries use just one yeast for everything.
It can make a variety pack or a tasting flight somewhat dull, in my opinion. On the business side, it makes economic sense. Its just another reason I usually prefer homebrew over commercial beer.

As mentioned many breweries have a house strain that they brew most of their beers with, usually a neutral ale yeast, but it only works to a point though as there are certain styles that can't be made without the right yeast. Rogue for example uses Pacman for almost everything but they use a Czech pilsner yeast for their Imperial pilsner. The Deschutes house strain is an English ale (supposedly Ringwood I hear), but they use a Belgian wit yeast for Chainbreaker. Stone has their house strain but they use Belgian yeast for Cali-Belgique. The list goes on.

Edit: it also doesn't have to make the selection dull, I would never say that about Stone or Rogue for example. I mean, Voodoo Doughnut Lemon Chiffon Creuller Ale??

Also that`s not an especially good brewery... Markets mostly to tourists.