Then all I can say is, you aren't as much of an opinionated gobshite as me.
If someone gets given a turd for free, they won't be trying to tell people it is the tastiest snack in the kitchen. Not if they have any self-respect anyway. That is just a sure-fire way to make you look like a twat when people find out that you're talking crap.
OK, it might colour an opinion slightly. I might feel bad about rubbishing something too much because I liked the shop, the owner etc so I might be a little kinder in my words. But you're never going to get a rave review about a pile of shit just by giving something away for free. Or at least, you're not going to from anyone who places ANY value on their reputation.
You realise that you've just proved my fucking point?