the problem in land clearing is that some low-baller may come in and really wreck a property. The customer ends up with a piece of land that has been virtually raped. Save trees are damaged or scorched including root damage. Often, erosion takes place because the lowest bids are almost always conventional clearing (dozing and burning here in Texas).
There is also a huge difference in quality of clearing when using forestry mulchers. I wouldn't take on a 1000AC job with one small machine unless the customer knew it would take a LONG time and I'd still want to shear and chip the big stuff.
Around here, everyone seems to have gotten into the mulching business. I see the results daily. Some jobs look great but many look awful. The ones I have been underbid on do not have the finished look that I personally strive for. maybe the customer was looking for a rough cut and a cheaper price but often, after visiting with me, they do not communicate that but rather, they are looking for the "park-like" look which takes more time, more finesse, and the right equipment.
The cheap guy will always be there. At least in Texas, there aren't any laws protecting people against stupidity, ignorance, or contractors who lie. It's buyer beware and the best we can hope for is to be recommended to a friend of a customer or get work trying to fix the other guy's mess. And yes, I do offer a slight discount to fix another contractor's mess and it helps get the relationship started.