Generally ... I go to a lot of company meetings and investment...

Generally ... I go to a lot of company meetings and investment presentations and I know there are a lot of people that don't read posts on hotcopper or post on hotcopper. There are many other sources of information that might cause an investor ( or trader ) to look at a stock beyond what is posted on hotcopper. People make their own investment decisions. It takes much more than one poster on an internet forum to cause the massive volumes in a stocks necessary to cause a significant and sustained rerate of a share price. Announcements are put out, people read/analyse them (and make their own decision whether to buy), volumes show up and then technical traders and bots arrive. In the case of MUS there was also a convertible note provider that likely had bots aggressively working swings or uplift in the share price. MUS management were also putting out ruby price expectations in videos and verbally at company meetings. There was a huge amount of discussion by many many posters on hotcopper. Traders also quite regularly threw in their targets and expectations with their charts.

As for the collapse of MUS. That's largely been caused by incompetent management.
Even with ex staff and consultants from their neighbour gemfields they weren't able to successfully organise their auction. They botched the sorting of the rubies into appropriate lots to achieve better sales prices for their higher-value stones ( buyers didn't want to buy lots that had inconsistent groups of colour / clarity / grade ).

MUS certainly had quality Ruby tenements ( sold for over $13M ). $10M of this in shares but the $3M cash went to Regius Management that were on the MUS board ( nice sweetener for them ). It was the ex-COO of their large competitor Gemfields that negotiated the sale to Fura ( quite sure that he knew the tenements were worth something ).