Everyone has their own ideas and methods of how to prepare for the street. Sadly people criticize methods that are not their own and they think of their own method as supreme.
One method is not better than the other. When you say, that is not as realistic as my method, you are essentially saying, your method is not as good as mine. This is ego talk. This is having a superiority complex.
If your going to give advice and say why don't you do this to make it a little bit more realistic? You have to be very careful when giving advice or your going to be disrespectful. You don't walk into Bill Gates house and say let me give you some advice on how to make more money.
Can I train in a sport and then transfer some of that into the street? I don't see why not! There are benefits such as being able to perform and execute a game plan under pressure. Being able to deal with and give back aggression. Mentally staying focused and not give into self doubt. Getting fit and becoming an athlete. All these things can help you on the street.
There is a saying that is often misunderstood "You fight how you train".
Yes you do fight how you train, but it's not that literal. Boxers skip rope, they do ab work, they go running, but when they fight, it doesn't look like those things. Do you know who else uses the jump rope? Little girls, but Boxers don't fight like little girls, and little girls don't fight like Boxers, even though they can both be very skilled with a jump rope. I never see a Boxer start doing sit ups and crunches in a fight.
"If you train in sport, your going to get yourself killed if you try that stuff in the street" I'm sick and tired of hearing this.
If I train in sport for the street, if I train in traditional MA for the street, if I train in modern urban tactics for the street, each one of these things is a single method, each one is a simulation for real combat. There is a plus and minus to each method. One is not better than the other. I think it's more important that you learn how to benefit from each one and go get some experience in all these methods.
Bottom line is be humble and respectful. No matter what style(s) you practice, don't make big claims and don't put down other people's methods.