Do scholarly differences on an issue mean it's permitted (mubah) in Islam?

Some people regard disagreement in an issue as an evidence in and of itself of the permissibility of something. So for example, a fatwa will be passed that something is impermissible, and someone would object: “Why do you say it is impermissible, when there is disagreement in it?” Thus, disagreement is made a proof of permissibility, and not the evidence of sharī‘ah or the superiority of a mujtahid holding the opposing view. The jurist Al-Khattibi transmitted from one individual: “Since people differed about intoxicating beverages, and they reached consensus on the prohibition of grape wine and differed over the rest, we will declare what they agreed on to be haram as being haram and declare everything else as permissible. This is a despicable error. Allah has ordered those who differ to refer that which they differ in to Allah and His Messenger… If what this person said is correct, it would necessitate the like of it in riba, sarf and mut‘ah, as the ummah differed in these!.. Disagreement is not a proof.” (al-Muwafaqat, 5:93) Shatibi further explains: “The one who says this is in essence following his desires and is making the agreeable view a proof in his favour and something to ward off criticism from himself. Hence, he is taking the view as a means to follow his desires, not as a means to piety. Thus, this is extremely far from compliance to the orders of shari'ah and is much closer to taking his desires as god.” (al-Muwafaqat, 5:94)