"it's more plausible" is a correct and usable phrase in written English
You can use it when you want to express the opinion that something is more likely or more convincing than something else. For example, "I know it sounds crazy, but it's more plausible than the other options we've discussed."
It's more plausible that Facebook's location application will federate other location streams (such as Foursquare's or Gowalla's data) at first.
It's more plausible to argue that the ad buys just didn't make that much difference.
It's more plausible, in the film, that Edward De Vere wrote them, even though he died nine years before the last Shakespeare play was written.
It's more plausible partly because it tracks with another unhappy New York dining phenomenon at some remove from the languorous pleasures of Manet's "Déjeuner Sur L'Herbe".
Not sure if I buy Eric's explanation of his beating of Paul West as a bit of rough sex-play gone bad, but at least it's more plausible than the football argument story he originally went with.
It's more plausible to suppose that we first grasp what truth is, and only subsequently figure out what truth-makers are required for the various kinds of propositions there are (Horwich 2009: 188).
Actually, it is more plausible than its model.
It is more plausible to believe that Mr Sharon's real intention is to do away with the Palestinian leader and, more important, with what remains of the Oslo peace process.
But it is more plausible to blame the trial's flaws on a legal system that has only imperfectly made the leap from being venal and biddable under dictatorship towards judicial independence and due process.
This can only be a guess, but it is more plausible than the alternative guess that America's going will nudge Iraq in the right direction.
Despite that conclusion, it is more plausible that higher intelligence relates to one's willingness to identify oneself as gay and to participate in research studies, rather than that higher intelligence relates to homosexuality per se.
