Actually more than a few people have said that.
The percentages may be stacked against him, but the percentages don't look any better with Schaub, do they? Furthermore, if you play him and find out he sucks, it helps the future decision making process.
In all actuality, I want to see Schaub benched for a game, or a half, or hell, even a series. I don't necessarily want to switch QBs mid-season. That's likely a recipe for disaster. But at this point, playing Schaub looks like a recipe for 8-8, which is worse, IMO. At this point in time, with the way this team is built, either be great or take the next future step toward being bad. Keenum is that next future step, IMO. He either succeeds or he tells you all you need to know about the position going forward.