Like most industries, cleaning has standards and governing bodies to which professionals can join to make it easier for consumers to know exactly what they’re getting and keep standards high, especially when health is a related aspect. It’s not illegal to be unqualified and offer carpet cleaning as a service, not like other industries, but like most services cleaning is actually a detailed skill and has qualifications and standards. Why wouldn’t you use a professional when it comes to your home or health? No one would hire an unqualified builder for a major renovation after all.