Think the first straw could be Steemit Inc shutting down or otherwise deprecating public RPC nodes.
Second could be public RPC node providers to begin shutting down nodes as load cost continues to mount likely prompting a user exodus and probably sell off -> market crash.
Last straw will be private node operators to shutdown as well as witnesses. Steem will then be a memory.
This is my "doomsday scenario" but I'm not all doom and gloom. I see potential opportunities in all of this to rebuild.
We need to start staging and deploying our backup strategies now. I've already tweeted /posted to this end and to my surprise. @CA_dawg was diligent in putting together a massive repo of forks.
Steem, condenser and much much more.
Think we are gonna be fine ultimately but there does seem to be a storm brewing imo.