The overwhelming majority of the citizens of Washington, D. C. are employees of the federal government. As such, they are not taxpayers, but rather the recipients of taxes paid by other people. Whatever taxes they nominally pay are merely a deduction from the tax proceeds they have received. All of the income they obtain and keep is from the proceeds of taxation.Perhaps denying the citizens of Helengrad the 'right' to vote would perform a similar service here.
Denial of the right to vote to citizens of Washington, D. C., serves in some measure to protect the taxpaying citizens of the United States from the depredations of those who live off their taxes and who would like to tax them still more.
LINK: No Representation for Taxation - George Reisman's Blog