EITC is only one way of reducing the tax paid (credit).
Parttime workers (Seniors and others that have to be limited for one reason or another)
Students (educational credits)
Graduated Students - Loan paybacks w/ low income
People who are under the minimum threshold bracket (income level and/or IRA contribution)
People that have large amount of dependents. (4 adults can reduce taxable income by $1+2K.)
Many of those that are on public assistance end up with no tax liability having no declared income. Otherwise, they would not qualify
To address your points sequentially:
- Part time workers still pay taxes but are afforded the standard deduction which may reduce their liability to zero (depending on filing status and joint income if married)
- Students that are working and earning an income are still paying income taxes that may be reduced to zero depending on income earned levels
- People under the minimum threshold still pay on the income while it is earned but will likely have a refund (or possibly even greater) based on a standard deduction
- People with a large amount of dependents may end up not paying if they earn less that $43k/yr (joint filing ($41K/yr individual)) taking standard deductions
- Those on public assistance do not have to file returns. They are not part of the equation.
The entire point of this argument is that the 47% is a bogus strawman because the EITC only accounts for ~16% of taxpayers getting out of a federal tax liability.
All of the other scenarios that you mentioned are most likely going to negate a person's federal tax liability by the filer taking the standard deductions filing a 1040EZ or a 1040A without itemizing.
That very same option is available for 100% of all filers which is why this is a strawman argument. If those making more than the $43K/yr wanted to file in the same manner that this mythical 47% are, they can. They would end up paying a shitload more because they wouldn't be itemizing, would lose their ability to claim mortgage interest, losses to offset capital gains, medical deductions, etc., but they could do it. They chose not to because, while it helps the poorer filers, it hurts them. But it sure gives them a great logical fallacy of an argument to try to beat them over the head with.