Why?
Normally Lame Ducks take a caretaker role doing the bare minimum to keep the government functioning until the new President is sworn in. Obama has done several administrative and political actions that seem to be giving everyone the "finger".
The issue of tossing out Russians over the hacking seems to be silly because hackers can be based any in the world. So tossing out a few bodies looks good for getting a perp walk in the media but not much else. Also, in Pennsylvania, the judge throw out the recount claims of hacking after reviewing the PA procedures and practices. He found that the alleged hacking was a fiction in the minds of Stein and her funders. Since other states follow similar procedures and each state has its own system hacking an election is not that easy. Each state will have different equipment, methods, and procedures. Thus to hack the election, the Russians would need to guess which states are going to be critical to hack and figure out appropriate methods to hack each state. In the case of PA, the state allows, apparently, each county to use one several approved methods. So in PA you would need to hack at the county level. In the US there are about 3000 counties/parishes/boroughs (states are inconsistent in their terminology).
Also, in Michigan the recount found major problems with Wayne County (Detroit) unrelated to hacking; more like old fashioned ballot box stuffing. In Wisconsin, the recount (again no evidence of hacking) increased Trump's total by about 150 votes - a reasonable swing statewide for either candidate.
Applying Occam's Razor, the Russians are interested in the outcome of the election. They will attempt to hack political parties and campaigns probably for information. They are not likely to have the fine grained local knowledge to stuff the ballot box successfully. These comments can probably be said about any competent (and most incompetent) spookhauses.
So the better question, is what does making the Russians the evil heavy gain the donkeys? Trump does not seem to be enthusiastic about getting involved in any shooting wars. So unless his hands are tied, he is likely to have a very different policy in the Middle East. This means US policy towards Russia will be changing to probably a less hostile one.