Well For me it depends on the establishment, however for the most part I agree...and it can be extended to Shopping Malls as well.....
I as well as my GF get very annoyed when we go out for the "quiet night" and have it disturbed by either a family with annoying children who are crying..but then again what can you expect from a child which is under 8yrs old...personally I blame the parents for either not taking them to a more child friendly resturaunt..or for not leaving them at home!!!...
I also get annoyed at those though who purposly move away from you for reasons of privacy in a public returaunt....
For example this valentines day I went out with my GF to a very nice Italian resturaunt ($40+ a plate) and we were seated in a corner two tables away from a young couple...well 10 minutes later they sit an older couple right next to us, well after two seconds the woman in the older couple decides that she does not want to sit next to us and moves a table over next to the other couple (I think that she felt people as young as us should not be dining in such a place and did not want to be next to us)..well after sitting there for a few minutes she requests that they then be moved again to the opposite side of the place...well 10 min later they sit a party of 8 younger people right next to them...both myslef and the other couple laughed as she got what she deserved!!!...
but then in the same place a family showed up in jeans!!! and they were seated right next to us...a father and mother and two children who were under 8yrs old and obviously not happy to be there...why would you ever bring young children to a place like that and spend that kind of money on food they will never like???? makes no sense to me!
I think that I would frequent a resturaunt with that type of rule though...however I am also annoyed by groups of people getting loud and drunk at rather nice places...good way to ruin an evening is by listening to a bunch of loud people sluring their words and spitting out food due to their drunkeness..save getting loaded for the bar is my opinion