I think that as long as a) the effects of the measure were well communicated and b) there were no significant impediments to actually voting, then the percent that vote is immaterial and the result of the vote should stand for everyone.
After all this is the way the US conducts its elections. Many elections have very low turnout, yet the results are binding.
I think there's a difference between the result being binding, and that the vote stands for everyone.
Abstaining leads to your opinion not being represented, which is to be expected. It doesn't follow that therefore other people's vote hence represent you.
For the vote mentioned in the article, which is non-binding, non-enforceable, and ridiculous in its scope, I'd guess that most abstainers' real opinion on the matter, is that it's a waste of their time to participate.
People have their own reasons for silence, even when a referendum is nonbinding. Interpreting that silence as consent or approval is the moral equivalent of a bulldozer.
After all this is the way the US conducts its elections. Many elections have very low turnout, yet the results are binding.