Not so much unrealistic, as there is a difference between sparring in a sport setting versus a martial art setting, and each has a different value and aim. Your definition of sparring included things that we all consider sparring, but the question is sparring in preparation for what?
If you are training for stop-point karate, WTF Taekwondo, or BJJ tournaments, then sparring in those idioms is entirely realistic: you are preparing to fight under a specific set of conditions, and to train differently would be counterproductive. I do, however, consider such tournaments and the preparation that goes into them to be firmly in the territory of games/sports.
Nothing wrong with them, and certainly, there is enough crossover with actual fighting that a person who is extremely competent in any of the three will certainly not be bereft of tools in the even of a violent encounter.
Same holds true for boxing, but boxers don't make a stink about whether or not boxing is an MA the way that sport taekwondoists do regarding the WTF tournament style taekwondo. Maybe because no belts are involved?
There needs to be some element of aliveness and randomness at some point in training, regardless of what you want to call it, and that element needs to be, within the bounds of reason, not artificial in its design.
WTF sparring is an artificial type of fighting in that it artificially makes high kicks predominant and eliminates all of the real world consequences of using high kicks.
Point-stop karate is less artificial in that it allows greater use of hand technique, but is highly artificial because it presupposes that you've killed your opponent with a punch or a kick and thus you stop fighing after scoring a point. And of course, it lacks grappling.
Boxing is less artificial. Yes, it focuses on hands, but that is what most people are going to naturally use predominantly anyway, and boxing is continuous, but boxing eliminates kicks and grapples entirely.
BJJ, judo, and other forms of wrestling are artificial in that they eliminate all strikes.
MMA is the least artificial in that it allows the greatest breadth of techniques, but it is still artificial in that it is set up in such a way that a grappler will have certain advantages.
Finally, all of them share the element that you are in a one on one, controled physical contest with another individual and the element of escaping is entirely eliminated.
Now, I am not disrespecting these sports. And yes, they are sports. They're hard, and if I jumped into the ring in any of those sports, I would probably be just as out of my element as if a WTF fighter jumped in to the shaijo to fight against me in a kendo match. And yes, I realize that kendo, karate, taekwondo, judo and BJJ are all considered martial arts. But the tournament fighting that these arts are associated with are sports. Plain and simple. Nothing wrong with that, but people do not like to admit it.
I suppose then that what constitutes a martial art and where the line is between sport and MA needs to be considered, but that is a different discussion that I will not get into in this thread.
I'm also not going to get into the whole 'they'd die on the deadly street' because I have yet to hear a convincing arguement that TKD/Karate/BJJ/Judo/Wrestling/Boxing/MMA athletes would indeed suddenly become incapable outside of the ring. I think that all of them have the advantage of regular training with resisting opponents, something that most people do not have. But their training is very specialized in a way that it would not be if you were preparing soley to defend one's self in a non competition environment.
Anyway, the only two scenarios that I felt were completely unrealistic were the fitness oriented class and the 'larping', though MA based fitness programs do not masquerade as self defense, while the last example that I gave (larping disguised as MA) does. The fact of the matter is that if your techniques only work when your partner allows them to or on your own students (no touch KO's anyone?) and you never train with a partner who offers any real resistance, then that is unrealistic and amounts to larping.
Hope that makes sense, as I kind of felt like I was rambling a bit.
Daniel