I think that some people are just genuinely modest liam to be honest, so I personally don't find this a good idea at all. I see what you are saying, but to my mind,more concerning than those modest people who undersell their talents are those who describe themselves as 'expert' when clearly they are not, however others may take their words and advice as that of an expert.
The level of knowledge we place ourselves at is only a gauge of how we see ourselves, and like anything, it depends on your basis for comparison.
for example, despite keeping over 30 syrians, breeding, showing and caring for the little critters for some time now, I wouldnt think of classing myself as an 'expert' I would be too embarrassed to do so.
Mind you, I also know many people who I would class as experts including the chairman and committee of the National hamster club, and I can just about guarantee that they wouldn't class themselves as expert either