The point that is being made here is that a Sufi master should not choose the side of doubtfulness and ikhtilaaf over the side of caution. So, even if there are differences of opinion on the matter, there is no difference of opinion on a full beard being sunnah. The differences only exist for the minimum required length, whether it be stubble or a fist length, while there are no differences of opinion on fist length and beyond. If we go to a restaurant and there is doubt about whether the food is halal or not, we would always err on the side of caution (hopefully...) and not eat the food. Why can we not do the same when it comes to everything else and "err" on the side of caution? We always err on the side of caution when it comes to our health and our wealth but we always say that there is ikhtilaaf on matters of deen and then err on the side that may or may not be contrary to the deen. Since there is ikhtilaaf, there is just as much a chance that it may be sinful as it may be permissible but then, you see the dichotomy that is created? Permissible vs sinful. It isn't beneficial/mustahabb/sunnah to have a short beard but it may be sinful. Shouldn't we try to avoid the possibility of sinning if we're going to be teachers and helpers to others in the path of deen? If you know for certain that a certain Hanafi shaykh regularly delays his Dhuhr salaah to such an extent that it is 'Asr time according to the other madhahib but still Dhuhr in the Hanafi madhhab, would you go to such a person for spiritual betterment (and let's not even mention that he isn't at the masjid during jama'ah times)? Even then, it is a lot easier to find excuses for such a person than a person who cuts the beard. I remember when there was a big program in my city a few years ago, with many amazing ulama who came from around the world to give lectures. There were thousands of people who showed up to listen. During the question and answer session, someone noticed that the ulama were not drinking water in three breaths so he wrote down his observation and sent it up. The ulama did not respond by saying that it is the internal aspect that is more important than the external or that it is the intention that matters - they admitted that they had forgotten and did not repeat this - despite the fact that it isn't makrooh or haraam to not drink in three breaths/sips. The ulama are held to a much higher standard. When you ask people like myself who aren't laymen about the length of our beards when we discuss this issue, you should realize that we are not ulama. Even if we may or may not have sunnah beards or sunnah clothing, people do not look up to us for spiritual guidance since we are jaahil. No one says that fulaan shaves regularly so it must be okay or that fulaan listens to music so it must be okay - but when they see a scholar, someone who has 'ilm engaging in these things, then they become "excuses" by the laymen when they want to do the same thing. I am happy to say that I'm a jaahil when it comes to telling laypeople anything about Islam since I don't know any better, but the ulama are the standard bearers of Islam and should be as close to Rasoolullah in their emulation of him as possible.