Your comparison of QuickBooks to TurboTax is flawed.

You state: "Also, TurboTax has the option to set up a password when accessing your account. However, this isn't that necessary for it doesn't contain other personal details."

That is not true. Both programs store very sensitive personal details.
In fact TurboTax's personal details may be more sensitive than those in QuickBooks, especially for those QuickBooks users, like me, who don't use the payroll function at all and have no need for SSNs in QuickBooks. We rely on an outside payroll service.

If the password is optional for TurboTax, why shouldn't it be optional for QuickBooks??
Your justification that "this isn't that necessary for it doesn't contain other personal details" is just plain wrong. The sensitive data that QuickBooks detects exists to the same extent in TurboTax.
In both programs you may find the employee and employer Social Security number, but in TurboTax it is absolutely necessary for the program to function properly, while in QuickBooks, at least the way I use it, it is not necessary and in fact I don't enter any Social Security numbers.
Same for the employer EIN. Necessary in TurboTax; not used by me in QuickBooks.
As for employer bank details, I don't use them in QuickBooks, but in TurboTax I need my even more personal taxpayer bank details in order to e-file a return.
A vendor tax ID may be necessary to fill out 1099s in QuickBooks, but third-party tax IDs are just as necessary in TurboTax to input Schedules K-1 and the various laundry lists of 1099 forms (the common ones being MISC, DIV, INT, R).

So, with all due respect, your logic is wanting.
And I hope that my pointing out this information to you does not result in the worst of all solutions, imposing an equally heavy-handed password  system within TurboTax.

I'm in complete agreement with @dskurth. Let your users use your programs the way they want to use them.