From what I can gather having read a shitload of posts dumping on MG, most people don't like it 'cuz it's not very newbie friendly. You won't need to add ferts for at least a month, and if you use MG ferts after that, use them at 1/4 strength to start.
Miracle Gro works. It's just that there are others that work better, or are more forgiving for newbies like us.
Most people don't like it because it's cheap, and will kill your plants quick if you fuck up. And most new growers DO fuck up. I know that my first grow (of course it was MG) everyone told me to use a fraction of what MG recommended, and I was thinking to myself that more is better, so I used it full strength, with the same predictable results. I killed off 7 out of 8 plants. The one survivor is a testament to the stamina, hardiness and constitution of this strain. By all rights, it shouldn't have lived, but it did and gave me some really nice bud for all my trouble.
I'd say that most new growers go for MG because it's relatively cheap, and readily available. Most new growers are also extremely over attentive, and almost invariably start ferts right away, or over do them when they DO start feeding.
That would explain the high failure rate with MG. Used in moderation, I don't see why it wouldn't do as well as any other chemical fertilizer. It's DEFINITELY not for the beginner.
Maybe thats what we need to do, steer new growers away from MG until they know what they're doing. Of course, by the time they know whats up, they'll know that there are much better ferts out there and won't even go to MG at all.
As long as MG is so readily available (and cheap), and as long as there are impatient people who want to grow their own without doing any research or go thru much effort, we are gonna hear the horror stories of failed grows.
THIS is where the true grower emerges. Either they give up, or study the failed grow to figure what went south and learn how not to repeat that.