After thinking about it, the name seems rather inappropriate because the majority of users of the tax software are not "accountants".  72.7% of PTIN holders are not CPAs.

https://www.irs.gov/tax-professionals/return-preparer-office-federal-tax-return-preparer-statistics

So I guess that Intuit wants to exclude 72.7% of potential customers.  Maybe Intuit is saying the major of their professional tax customers should go elsewhere.