Three problems:
- Money. Reasonable restaurant buys decent bottle of wine for £10 & sells it for £30 = £20 gross profit. The equivalent in beer (at least in alcohol units), let's say, is three or four 500ml bottles at 5%abv, cost price £5, selling price £12-£15. Gross profit to restaurant of £7 to £10 and customer moans about the price of the beer.
- Image. I won't re-tread this well-worn path.
- Ignorance. I won't re-tread this well-worn path either.
I work for a wholesaler which has to try to address these questions every day of the week. We sell decent beers to umpteen restaurants but generally they are the type with a bar attached at which sales are seen as a bonus on top of the dining with wine. Straightforward dining restaurants really CBA stocking beer mainly because of problem 1. Sadly same restaurants will usually keep a beer in stock but normally an international bland lager (70p/bottle cost £4 selling price approx) with the mistaken rationale "lots of people drink it so it can't be bad".