We contend that the reason people dislike hypocrites is that their outspoken moralizing falsely signals their own virtue. People object, in other words, to the misleading implication — not to a failure of will or a weakness of character.The authors blame the issue of honesty: hypocrites signal virtue that they do not have
I don't think this rightly identifies the reason we dislike hypocrisy, though in part this may be due to the definition of hypocrisy. From the abstract
We propose that hypocrites are disliked because their condemnation sends a false signal about their personal conduct, deceptively suggesting that they behave morally. We show that verbal condemnation signals moral goodness (Study 1) and does so even more convincingly than directly stating that one behaves morally (Study 2). We then demonstrate that people judge hypocrites negatively — even more negatively than people who directly make false statements about their morality (Study 3). Finally, we show that “honest” hypocrites — who avoid false signaling by admitting to committing the condemned transgression — are not perceived negatively even though their actions contradict their stated values (Study 4). Critically, the same is not true of hypocrites who engage in false signaling but admit to unrelated transgressions (Study 5).Hypocrisy is more than not practising what you preach. Paul noted that some preach the gospel out of envy and that, motives wrong, at least Christ is preached (Phi 1:15). Their false virtue signalling, while rejected by him, did not put him him out of sorts (though perhaps Paul was able to identify a benefit that most cannot?). I am not so sure that we dislike hypocrisy because we encounter people fail to live up to what they claim.
The issue of hypocrisy is more in the condemnation aspect of it. Hypocrites do more than just fail to live their morals. Rather that they exempt themselves from the rules for specious reasons while asking others to abide by them. It is as if you and they are being judged in the same court for the same thing and they are the judge. Then they condemn you and acquit themselves.
It is an attack on justice. Not so much an issue of honesty, that they falsely claim their virtue; but an issue of injustice, where a hypocrite demonstrates that he is, in fact, an unjust person and yet he takes on the role of judge and jury.