I haven't had a burger at Wendy's since they did the "Daves Hot & Juicy" promotion a few years ago. The "juicy" was more an unpleasant greasy and the meat was kind of dry.
In northern Italy there are a number of traditional dishes made of horse meat and served in the nicer restaurants.
I love Nandos -- and remember, you get what you pay for....no chance of ingesting any "meat glue" from their bone-in chicken.
People have been using binders and fillers to stretch out meat and turn small bits into reasonable servings for centuries. Think meatballs, croquettes, sausages, terrines, etc. Eggs, corn starch, flour, bread, etc. all serve as binders to glue together small bits of meat into something that looks more like a serving of something. People have been using enzymes on their food as a tenderizer for centuries as well (papaya and pineapple juice in a "natural" recipe, Adolph's meat tenderizer for the modern home cook), so that's not new either. Advances in food science introduce new products every day and this is just the latest set of additives.
I find it hard to believe that someone would go into a nicer restaurant and not notice if they were served trimmings glued together with transglutaminase or Fibrimex instead of a steak. Either the flavor or the texture (or both) would make it pretty obvious that you were eating fused meat. If it's palatable then people will buy the product. If it isn't then they won't. Arby's has been selling fused meat as roast beef for decades. It's obviously not real meat, but people eat it anyway.
Now, if you really want to ponder food chemistry....how come when you buy a loaf of bread in the UK it starts to mold in about a week while a loaf of bread in the US takes nearly a month to start getting the green fuzz?