There is a lot to be taken in from this one. I'll try to organize it a bit:
The technical bottleneck. I'm a developer too and, from this position, I can tell you that nobody is irreplaceable. So, even if @dan left, that doesn't mean the STEEM blockchain will die. It may take a bit longer, we may hit some roadblocks, but it will survive. I also watch what @dan is doing with EOS and I think it has a lot of potential. What lacks in EOS, though, is exactly what's already in STEEM: adoption. There are hundreds of thousands of people already using STEEM.
The suitability bottleneck. I like the idea of a SRT (Steem Reward Token) but I do think the processes involved are a bit more complex. The current SMT implementation is suitable for a specific set of processes, namely the ones involved when you publish and share content. Of course, you can still use this part in other processes, but that doesn't mean it will substitute it completely. I don't really see and WebMD on top of Steemit, but I can see an SMT measuring the engagement related to medical content.
The scalability bottleneck. From all the potential problems, this is the most difficult to tackle. I ran a content node, I currently run a witness node and I know what it takes, from a hardware point of view. This thing is greedy. So, unless there is a fast and reliable sharding solution, one that will involve fragmentation of the blockchain in a way that it will make it affordable to run a block, Steem will either collapse or it will become badly centralized, in the same way ASIC hardware centralized the mining market. What I mean by that is that it will be extremely expensive to run a content node, with RAM requirements in the Terabyte range.
Other than that, SMTs are a huge development and as any disruptive development it can go extremely good or extremely bad. It's all about execution now.
Thanks so much man, comment truly appreciated as it throws great insights on to my freestyle thinking here. All valid points, time will tell, it is all so exciting.
I saw a fantastic 90 min interview of @Dan by IvanTech yesterday, i just love this guy, he is really pushing the possibilities and it will be all on github on 1st of June. Once it launches, it will be out of his control, crazy times, crazy projects, we are blessed.
xxx