The 'hobby' aspect doesn't really matter, above a certain turnover threshold* any business must be VAT registered, below that level they just pay the VAT on their supplies and can't claim it back.
* currently £82,000 in UK and €75,000 in Ireland - so, around €1,500 a week turnover.
At the risk of being 'political', a lot of people from GB do tend to think that the rest of the world should be in tune with them. When I used to travel over as a foot passenger, there were always people on the bus to Heuston and Connolly that were amazed that they couldn't (officially) pay in Sterling, although the driver would always facilitate them. That would not happen over here.