Russia has some incentive to have Trump become president, but the lengths it would go to for that to happen is debatable. This can arguably be a conspiracy theory born out of modern anti- Russian or anti- Trump propaganda. It can also be true.
The more significant aspect of this issue is that it involves the integrity of the American voting system. People are preoccupied over who did it, that they forget that it is being done. If the public is not able to vote accurately for who they truly want elected then the idea of American democracy, played out in the real world, begins to fail, because the heart of that democracy, the ability to vote, to choose elected officials, is compromised.
That factor should resonate with Americans more than who is responsible.
That isn’t to say, however, that the perpetrators should not be caught.