The premise is a little shaky: start a business by debunking all of the industry hype and foolishness that makes the industry highly-profitable in the first place. Replace questionable and high-markup products with the most precious resource of all, labor.
The TFP doesn't require daily testing. It doesn't prohibit the use of products other than liquid chlorine. The tenets of TFP are knowing what's in a pool, knowing what's being added, and understanding the interactions. I would think a pool service could leverage the wisdom provided by the TFP method. I'm sure the market can offer plenty of pool owners who don't want to brush and vacuum, nor join and participate in tfp, nor lug gallon jugs all over town yet desire the benefits of a TFP pool.
That demographic might be fine knowing that their pucks will require some water replacement. If their pool service can help them understand, calculate and anticipate that, that's a service in itself. Some owners might perform FAS/DPD testing and be willing to test that to their "consultant / brusher guy" for advice.
Knowledge is a good thing, but as pool $tores understand well, ignorance can be better for the bottom line.