Another way to look at it is that each other state's Elector selection process is their business. The Constitution does not provide any assurances that other states will choose their Electors by any particular process, but instead specifically reserves that for each state's Legisature. A state would be within their rights to choose them winner-take-all, in proportion to the popular vote, or by a random draw from a Powerball machine and you and I would have no say over it (as non-residents).
Similarly, the entire election is the business of every citizen. "Their business" has a direct impact on my life, so I should have some say in the matter.
>The Constitution does not provide any assurances that other states will choose their Electors by any particular process,
The Constitution sets up the electoral college. That doesn't make it a good system.
The voting power of Georgia residents may have been compromised here, but the voting power of the rest of the country was unaffected. In a popular voting system, that would not be the case (if the fraud increased reported voter turnout, seizing more voting power into the fraudulent election, for example).