"Vine’s business problems throughout the years – poor management from directors leaving every year, competitors such as Instagram implementing their own short video features, massive lack of innovations to keep users, and their biggest stars from jumping to other platforms." Seems to sum it up there: lack of innovation, adaptation, and forward thinking.

Not every model is sustainable and a great operating team may only be able to forestall the inevitable with some models. It's a duplicitous statement for @rus to speak for others in the sale of their company.

Summary of your summary: Poor management.

Vine provided an outlet for otherwise unknown individuals to create a name for themselves with minimal effort. Truly a shame that we lost this platform.

Was it uniquely better suited to doing so than other trendy new media platforms?

Vine shutting down strikes a particular chord with me, given they were responsible for shutting down the microvideo startup I helped build, Keek. Twitter getting into the game sucked all the financing out of the environment and we essentially starved to death before reaching monetization, since we were focused on massive growth.

We realized at the end that there was no way to make money in the space - and Vine shutting down basically proves that point.