Here's a speculative response. Since Russia would surely rather continue to pretty much do as they please, why would they not attempt to help the Hillary campaign, rather than Trump who promises to return the US to strength?
That's a really big question. Trump made no bones about his desire to strengthen the US military, while Hillary was following Obama's path of reducing American military strength around the world and appeasing, rather than defeating, our foes. Why indeed would the Russian government wish to back Trump and not her?