Except for the fact that:
1) stoning is a maximum punishment, not the only one.
2) we aren't to enjoy handing out such punishments. Much like Prophet Jesus' teachings above, we take the example of the Prophet Muhammad (saw) where a sinner admitted to adultery, but the Prophet told him to go away as he did not wish to administer the punishment, The teaching of justice being tempered with mercy is true in Islam just as it is in Christianity.
3) Accusation is one thing, but the punishment is for one who has been found guilty beyond all reasonable doubt in a court of law, with sufficient evidence.
Regarding cruel crime penalties. I would argue forever and a day, those punishments are indeed truly just for the most heinous and cruelest of criminals. For example, would you honestly give a serial rapist the same punishment as a common thief? I should hope that you are of a certain intelligence and do obtain a moral compass, to realize the difference in severity between the two crimes. As such, it would only be just to meet them both with appropriate punishments - not the same. One crime is clearly more severe and must be met with equally severe punishment.