If I'm making very little money, and I have equipment that requires a USB 3.1 charger, then it is even more important that my (expensive) equipment is not damaged - then, instead of being out an extra $7 for a charger, I've potentially lost many hundreds of dollars damaged by a out-of-spec charger/cable.
This is a very real problem: http://arstechnica.com/gadgets/2016/02/google-engineer-finds...
This wasn't that big of a deal in the Pre 3.1 era, because the power levels typically being supplied were less, and there was a broad understanding of the power levels that were going to be supplied.
You write, "Those people are going to look for cheap USB chargers, even if they are sub standard quality - and the market will fill that niche one way or the other." - and I totally agree with you, which is the entire reason why these certification programs are required - to ensure that only systems certified to be in-spec will be recognized.
My 10 Watt USB charger, that I've carried with me all over the world for 2+ years, powers up my iPhone, my iPad, and my battery-backups. I use it every single day, usually multiple times/day. I realize that an extra $7 can be a lot of money for some people, but, spread over 2 years, for something so important, it seems to be a reasonable investment.
It becomes an even bigger deal once you can also charge your laptop off the same charger.