If even a smallish percentage of key athletes/celebs/whatevers move exclusively to Instagram or something else, it would seriously disrupt Twitter. IG would love that, in fact.
Plus, how many people with over 10k actual followers are there really? Is $120/year times that number really going to make a difference for the business? Seems cheap and risky simultaneously.
Also, a lot of people would like a better anti-abuse system and some might be prepared to pay for it.
Really? You actually think Twitter has negative value as a company?
They have real revenue. Fire everyone except a few dozen employees to maintain the core services/ads. That'll let you collect at least $100 million in profit.
At a valuation of <$1 billion, Twitter would be a bargain.
I agree with your plan and would likely run the company like that -- except "just maintaining" a social network sounds like a long-term recipe for disaster too.
The share price would also tank with that plan, which of course won't fly being a public corporation. This is why they're in such a rough place.
It's an electronic wasteland and not the kind that makes money. I don't see how that ever changes.