Avatar, I totally agree with you. By the time these people have performed various tactics in order to avoid picking up:
stride on ahead ie I haven't seen it so can't pick it up
stand and gaze around and when sure that no-one is looking, just leave it
get a baggie out and pretend to pick up but actually leave it where it is ..............
I could go on but you get the idea!
But yes, I have seen the bags decorating the hedgerows and it does seem to be so stupid!
I really resent treading in dogsh1t when I always pick up after my own dog!
I often take the trouble to offer a bag to an owner who appears to have 'forgotten' to bring one out with them and sometimes they are grateful as they have genuinely forgotten. Other times I have been subjected to a tirade of abuse and told where to go! These people obviously think that the poo fairy is going to do their clearing up for them!