?...Because it's an important and useful tool.
I would stress that you hear more in Iron Mask, and that you hear everything on the right side which can't be beat for tone and crosshair ID , which is good. The less Iron Mask you use the more you hear.
I will use Iron Mask when hunting yard sized sites, and parks that I have plenty of time to work at hunting a small area at a time. Iron Mask is better for hearing targets than any other setting other than using a Clear screen. Since I hunt mostly by sound and in Digital, it's hard to explain what the curser is doing but I can say that the sound also jumps around just like the cross hairs do on the deep targets.
I will say that I personally don't recommend using it in every site, I really don't have to tell you this because you will know when you shouldn't be using it and how much you should be using when you do.
You could start out with Iron Mask set at say a -14 and then as necessary begin raising it to -13, then -12 and so on until it is set to what like. You do this to set the amount of tones you are willing to listen to, a quiet less trashy site for me means a -10 or -8, then the trashier the site the higher I will go to a point where I just switch to the preset coin program(it's pretty much overly trashy at this point and the tone from the iron and trash are unbearable, at least for me, others may have a higher tolerance).
I do mostly hunt with a custom coin program at this time because the site I have been working is impossible in Iron Mask, and I have been working it since day one because it's been producing lots of silver coins and V's, Indians and so on that I haven't had to move on yet. But when I do go out of the area or to the right kind of site for Iron Mask I use it to its fullest and the goodies start popping out as I would expect them to.
Just my take on it, GL/HH