The short answer is they are not dying but having a rough and tough time due to uncertainties related to current situations (e.g. softfork).
One thing is very clear about most of the tribes, specially 
Moreover, confusions with softfork and STINC's next action, FUD is running supreme among the Steemians. At this uncertain time, very few people want to risk into new asset class, tribe tokens. Thus buying pressure is diminishing.
Also, few investors are exiting to limit their loss or hedge some profit in fear that it can go further down or tribe tokens can become literally worthless.
Or, it is a golden opportunity to buy cheap tokens in "blood in the street" moment?
Since some of the content creators who treat tribes as an extra income by adding tag, they can afford to sell at any low price since they have no skin in the game. It is an extra pressure on tribe too.
It is very hard to sustain price of tribe tokens since they do not have brand image like Steem. Moreover, Steem is widely traded in external exchanges, on the other hand, tribe tokens are traded in Steem's internal ecosystem.
Another reason behind weakness of tribe token's price is that buyers of those tokens got saturated since Steem is not onboarding in en-messe.
Even the best developed and active tribe such as
Though founders have burned a large number of LEO regularly and have added lots of sinks aggressively, LEO is not able to sustain better price due to selling pressure.
Another problem with the tribe is that if big curators, miners or delegators want to sell their earned LEO regularly, it cannot sustain present price range due to low buying interest or illiquid market at this time. For information, investors have put lots of amount Steem who have bought miners or bought those tokens or delegated SPs at relatively good times.
SOLUTIONS
Best thing that can happen to these tribes is move to SMTs (if it is released in future) or has an SMT-peg, TRON10/20-peg. Then top ones such as LEO can be traded in many external exchanges where Steem or TRON is already traded. It will create demand for the tribe tokens outside of Steem ecosystem.
Onboarding still a major issue for both steem and tribe. Without onboarding large number of new investors cum curators, it will be hard to sustain reasonable price for such tokens. Tribes or blockchain based social media needs more curators than creators.
STINC's new owner 
Finally, the current FUD related to STINC's stake can be gone in coming weeks. If the optimum outcomes are achieved, then positive mode can return to steem ecosystem and investors can return to risky assets such as LEO or NEOXAG.
Disclaimer: This opinion is not a financial advice, it my personal perspective and opinion. Please seek professionals for financial decisions. This opinion is only for educational purpose.
Image sources: Most images are open sourced (e.g. Pixabay, Wikimedia etc.) with Creative common license. Some images are used with due courtesy to respected owners.
Thanks for reading.
Cryptominer , occasional trader and tech blogger since 2013
Posted via Steemleo