Externalities are real, and as such the discussion is about acceptable risk. So yes, in the most ridiculous and obvious sense it includes your kids, but you're assuming a lot too, and I question whether you're willing to reason critically - rather than emotionally - about school policy.
Not just kids learning verbal skills and to speak with masks on, but non-verbal-receptive kids, who rely more on facial expressions and visual cues.
For them, it's a double-whammy, because you're delaying their speaking and language/ listening skills further, but also depriving them of the alternative forms of communication that they rely on to cope with the primary deficits.
And that's before getting into whatever effects decreased socialization overall will have.
[1]https://www.usatoday.com/story/news/nation/2020/03/24/covid-...
Compare [2] to an estimated 216 deaths ages 0-4 and an additional 156 ages 5-17 from the flu in 2018-2019.
Those aren't perfectly comparable -- we took serious additional measures against covid that we don't take against the flu. On the other hand, how much actual masking of the 4 and under set is going on in preschool or kindergarten?
[1] https://data.cdc.gov/NCHS/Provisional-COVID-19-Deaths-Focus-...
I dunno what the right measures are to take for kids that young, but the difference we're seeing between the flu measures we (mostly don't) take and some anti covid measures for young children is hard to explain.
And any time someone says, um, the data appears to show that covid is not actually that dangerous to young children, you get people (who I'm 99% sure don't lock their kids in the house for flu season) having a fit that you're risking their lives.