If it was Will Solomon playing like Marbury did, would people be in favour of keeping him? Personally, I don't think so.
I don't like the assumption that Marbury will be much better next season. Perhaps he will. But why run that kind of risk?
And if we keep Marbury, what are we going to do with House? Play him at the 2? That doesn't work; it didn't work, it will never work consistently. Not playing House? We need his 3PT shooting, Marbury isn't enough of a shooter.
If Ainge wants a top 3rd string point-guard, able to manufacture offence in limited minutes, good enough to play 20mpg in case Rondo gets injured, talk to McIntyre's agent. Good defender, terrific shooter, good passer, good penetrator; he's leaps and bounds better than guys like Pargo or Tyrone Lue.