I totally agree with you. The way the communicate has to get better. I get that Minex wants to update the community with exciting news. But they have to think before actually announcing it. Because if you fail to deliver on promises it will only backfire. I just hope their newly hired PR firm will do a better job at communicating than they do.
On a side note still having doubts about this PR firm as their website does not look professional at all.
In my opinion, even hiring a PR firm still doesnt work this time, If minexcoin still doesnt have any working products yet. The time this project has fully developed and ecosystem works well, people itself will do the spread of word and even organized PR themselves.
A PR firm helps with the public relations, meaning they should have a strategic communication process that builds a relationship between the company and the public. So in other words a PR firm should be helping Minex by communicating better with the public aka the community. Like you and many others have mentioned Minex are lacking communication skills. So it's the firms job to strengthen the bond between Minex and it's community by communicating properly. After that is done well, the community can grow nicely without any concerns and become a media channel itself by using word-of-mouth.