why you dont put a voice chat in the game

i was playing Left 4 dead its an online game you can look for it in youtube , and it had a inside game voice chat we press on a Button to open the mic and we can talk inside the game, its a very important thing to communication inside the game sometimes the players freak out in some situations like if he is the last survivor or 2vs1 and he don't know what to do and there is no time to write for him or for him to read what others write for him so.... its a must thing that we have a voice chat inside the game
Report as:
Offensive Spam Harassment Incorrect Board