pupper there's more to muscle growth than just Protein,protein,protein.
Like 9cyclops9 said you need some healthy fats in your diet.
As for the soy protein being bad well thats debatable,i use quorn products occasionally and progress is fine no problems,there are plenty of articles/ studies praising the benifts of soy products just as there are ones saying its bad.
If used as your main source of protein then yeah you might get problems but if its part of a sensible eating plan then don't see the need to panic.
Its a bit like aspartame,i no some folks who avoid it like the plague and refuse to have anything that contains it,yet scaremongering aside ive never had any of the supposed side effects but i only have it in moderation 3-4 cans of diet coke a week.