Why would the RNC fight to hold traditionally Republican states if they think McCain is still going to lose? What difference does it make if Obama takes 370 electoral votes or "only" 320?
If you fail to hold your base, you're less viable - or not viable at all - in the next election. The RNC is looking forward to 2012. McCain may be burnt flesh (in the electoral sense), but the RNC still wants to preserve Sarah Palin and the rest of its potential candidates by this triage of resources.
It also doesn't want its voters to get into the habit of staying home or voting for Democrats.
Update (10/17): More tacit surrender:
After quick forays to the traditional battlegrounds Thursday, McCain and Gov. Sarah Palin headed south to states President Bush carried handily in 2004 and ones that haven't voted for a Democratic presidential candidate in more than four decades.Then there's this:
According to CNN's latest analysis of the electoral map, only six states are up for grabs (Nevada, Colorado, Missouri, Ohio, North Carolina and Florida) and they were all won by President Bush in 2004. That means even if McCain were to go 6-for-6 in the current tossup states, he would still fall short of the 270 electoral votes needed to capture the White House.