That's odd. I ride with East Sussex CTC and B&H Clarion, both of whom tend to stop at cafes or pubs. But there's an alternative for those who wish to bring their own snap, such as sitting in the sunshine in the churchyard (quite often). If you go to a cafe, you should be buying at least
something. OK, so I know what it's like to be very very poor, and count out my last pennies to see if I have enough for a coffee, but I recognise it's someone's job there.
As for eating my own food in a cafe, well, I admit I have done it on occasion
Mostly cereal bars if the puddings don't look so good. But I'll have eaten a meal there first, and I've done it discreetly.