Some people have dietary restrictions which prohibit them consuming inordinate (or even conservative) amounts of red meat. For such people, pastimes like grilling or even dinner at a pub can force them to make selections that are...well, less than ideal.
For others it may be a moral concern, but the texture and taste of meat is either something familiar or comfortable, which makes it desirable. Myself, I'm all for it. I like having options, and I like those options which may be (marginally!) healthier; check the sodium content of those burgers, though. God bless my hardening arteries, they're still not ideal meals for me.