Those are really open ended questions to ask and I think the thing here is that you need to do research on the topic and make your own decision as to whether or not it's good or bad.
Nutrition-wise, tofu pretty much aces: It's a complete source of protein (meaning that it provides all 8 amino acids). It has 0 fat and 0 cholesterol. It's low sodium. It's a source of calcium. Soy also contains isoflavines that might help prevent osteoporosis, and reduce the risk of heart disease.
However, lately there have been some studies that show a diet heavy in soy products can be bad as well - that the estrogen-like chemical can cause harm in unborn children and can affect men and women in a negative way if consumed in large quantities. Also there's some question about phytic acids in soybeans which blocks the absorption of certain minerals - and they recommend that babies especially not be fed soy based formulas because of that.
But you have to remember that if you eat too much of ANY food, you're going to run into some kind of issue like that. Our bodies are made to accept a varied diet ... that's how we get balance and why diets that advocate eating tons of one kind of food are generally failures.
This is something you're going to have to decide for yourself - do you eat enough soy that you should be concerned about this? Or is it a reasonable part of your overall diet.
I personally eat soy. I snack on edamame and eat tofu (sometimes) and I even sometimes drink soymilk. But I don't eat it at every meal and I don't consume insane quantities of it.
It's a decision you'll have to make for yourself - whether or not it's healthy. :
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