You forgot to mention that $90/h is the maximum upon team members. Based on their monthly burn rate ($200k/month) we can estimate that the average of their 20 team member receives at most $10k/month (unlikely, because they also have other expenses then salaries). $10k/month at 40h/week is about $55/h or $120k/year - including benefits (because benefits are part of the burn rate). It makes no sense to use the maximum team member salary and use this for every team member. According to m/2018/10/21/how-much-do-blockchain-engineers-make.html]this article, the average blockchain dev salary is more than $150k/year. So the average dev at Nimiq earns less than the average overall blockchain dev. If all these numbers are true (and I have no reason to assume the opposite beside you claiming so), this means that there is no reason to complain about salaries, as they are in no way extraordinary.

Your link to proof they do not work applies filters, removing those filters will improve the image a lot. Also you don't know what happens behind the scenes. For example the team says they are working on a new consensus protocol and this was also confirmed by a third-party (Reto Trinkler, Forbes 30 under 30). As this research is not public (yet), you can't see it on GitHub. Also other work outside of GitHub is not visible in your link. I am actually way more excited about new stuff and partnerships then about them changing existing code.... Oh: "merging commits of other developers" is called code review. It is one of the most important aspects of developing a secure application and takes quiet some time, so it's not a minor work.