I think the criticisms of the lack of access to Palin are perfectly appropriate, but I think it has less to do with Palin, as the critics seem to suggest, than with other factors. I would bet that if it were up to Palin, she would want the leash lengthened a bit. McCain's campaign people, on the other hand, obviously want to make sure not only of Palin's grasp of the issues, but also that she fully understands her role in the campaign and where McCain himself is on the issues so there is no confusion.
There are a lot of reasons you would want to keep the newly-acquired pit bull on a short leash, even if (and maybe especially) it wears lipstick.
Since her pick appears to have been a late game inspiration on the part of McCain, his campaign has to be nervous about her level of expertise--simply because she is an unknown commodity to them--as well as about her ability to complement McCain in the way they want.
Ten bucks says that if Joe Biden were at the top of the Democratic ticket and he picked a relatively unknown Black freshman senator from Illinois, the Democratic campaign people would be doing exactly the same thing--only liberals wouldn't be complaining about it.