What they don't mention is that this free filing offer is used by significantly less than 5% of the eligible taxpayers. Probably because Intuit advertises it very little and within the product very heavily hints that you should switch to a paid product instead.
If taxpayers aren't forced to confront the details of their tax payments every time they do a filing, they're less likely to complain about high taxes (this comes with the implication that high taxes are inherently bad, which depends on your political leaning)
Taxpayers may just accept the automatic deduction without realising they're being overcharged in the event of an error, for years at a time.
How much they actually care about such arguments vs the threat to their business model is subjective, but it seems the majority on this site (and myself) don't buy it.