The term big pig is usually put on a big round zoo creature of a fish that is revered, not despised.
I've heard it used on Bass too. Like big Striped Bass are referred to as 'Cows' in NE parts.
Personally, I think it does no harm, its just a pet name. I've used it. Don't see a problem.
Each to their own but a Big Wrasse in a small hole is like greased pig to land on light gear.
Me and Kev call small Bass sea rats and some people don't like that.
On the other hand, we treat our catch with 'respect'. Wrasse, Pout, Bass, all deserve to treated the same.
I even cut a dogfish free from a load of line the other day, and it must have been out the water for hours.
Now I know, people call those some horrible names, leave em to die needlessly etc.
So, sticks and stones and all that....
First time I heard them being referred to as a pig was years ago with my old mate Roy Newton, he loved his wrasse fishing and me and him would spend many a happy day collecting crabs and going to try for the rockies. The term pig was only used very rarely and we tended to only call wrasse over 5lb pigs, and that was when they had been tricky buggers to catch too. That man by the way, Roy Newton, was and is one of the funniest men that I have ever known, man did we laugh like kids for hours when we fished together, happy days indeed....I must phone the old bugger and see what he's been up to.
In the early 1980s I too used to fish with Roy Newton for rockfish, in those days there were plenty of 5 and 6lb fish and bigger. All fish were caught on hardback crabs,I nolonger use crabs, I dicided not to stick a hook in a crab again.
All my Wrassing now is with soft plastics, Jelleyworms, shads, boss shrimps,and more.
It is a real eye opener targeting Wrasse on soft lures,and you can lip hook them and put them back.
I have done this in Ireland,in Dingle. WOW. I had to go back for more.