Question about 50+1 rule in Bundesliga

My understanding of the Budesliga’s 50+1 rule is that it requires that at least a bare majority (50%+1) of a clubs ownership is held by its members, which I believe means basically its season ticket holders. This is held out as a measure to allow fans to check the power of outside investors. However, that doesn’t seem to me to offer much protection since an investor could still acquire 49% of a club’s shares, and would then only need the support of minute percentage of the remaining shareholders in order to do anything he or she wants. Is there anything I am missing here? I am only a casual follower of international soccer (i.e. football for non-Americans) so there may be some details that I am not aware of.