All I’m saying is; if you must feed your baby out in public, go into another room (nobody wants to hear the slurping or see the mess. (if that’s not possible, cover it up- all of it. And we don’t need any little ‘oops’ glimpses.)
If you want to be an exhibitionist, go home and do it in front of your husband or other interested parties.
Most of the general public is not interested and find it offensive.
But as for your objecion that a few babies nurse sloppily (you mentioned slurping and mess), consider that that applies to other blameless folks (people with cerebral palsy, very elderly people who cough or drool a bit) and that is no reason why they should not be allowed to eat in a restaurant or any other public venue. Their care-givers should of course be sensible and get them seated where they won't bother people or be bothered by people --- just as a sensible nursing mother would do.
But as for normal breasfeeding, it would be truer to say,
"Most of the general public is not interested and find it offensiveinoffensive." Most of the general public doesn't think a modest woman with a baby nestled to her bosom is gross.