Consumers don't know which certification is worth what. If you run a business you're always getting calls from bullshit consumer certification companies trying to extract money from you by playing on your anxiety about which recommendations consumers trust.

Competing with the government who can put the non-accredited businesses in question out of business or fine them a large amount of money is not fair competition for any private company... so that naturally leads to a monopoly as the OP points out.

See my other post.