State commissions required this pricing. And they still do. Their premise is that POTS should be as low as possible since by far the largest part of the population in their state is made up of residence users and also because of the desire to promote "universal service."
Even where telcos wanted to change the pricing model, such as by reducing or eliminating the pricing disparity between interstate and intrastate calls (intrastate calls being priced high, usually a good deal higher) commissions consistently refused to go along, since this would require raising POTS prices.
Business users are far outnumbered by residence users, and whether state commissioners are elected or appointed, they still ultimately have to represent and respond to popular sentiment.
Besides that, the premise that business users get more utility from telephone service is generally true.
Wes Leatherock snipped-for-privacy@aol.com snipped-for-privacy@yahoo.com