I have been rowing about discussing this on FB most of the day. The attacks on the cereal cafe are basically about bullying. There's a certain type of vicious puritan mindset that you get on both left and right ends of the political spectrum, which is all about attacking fun things first - before you fix anything else, make sure that you stop people enjoying themselves. The cereal cafe people have silly beards and are selling something that isn't necessary, therefore they are eeeeeevilllll!
The cereal cafe charges between £3 and £5 for a bowl of cereal. No one is compelled to eat their breakfast there. The local pub is likely to charge £2 -£5 for a pint/alcopop/spirit-and-mixer. Whether it's booze or weird imported sugar-coated corn starch, the nutritional value, necessity of consuming this particular stuff and the price are about the same.
Cafes selling healthy vegan raw organic food - or jellied eels and bacon rolls - will generally charge at least £3 for a snack and a drink, because they have to factor in the costs of heating, lighting, cooking, staff wages, premises rent and business rates on top of the cost of the ingredients. A lot of the paint-throwing dipshits are the sort of raging middle-class dickheads who have never actually been poor themselves but just hate everything - and think that 'working class culture' which consists of a high street full of bookies, pawnbrokers and dodgy unbranded burger bars needs to be preserved because giving the proles anything better would only upset them.