Yes, the anonymous accounts are a problem - but mostly because of the trolling, not the lack of identity. Snapchat and Instagram both have anonymous accounts and don't have a problem.

Yet Twitter has people like Kim Kardashian selling tweets for $200K/tweet[1] (so there's your measurement of ad-value), and yet Twitter can't make money.

Meanwhile, people are moving to Snapchat stories which is exactly the product Twitter should have built. Twitter, on the other-hand make the ground breaking decision to not include URLs in the 140 char tweet count.

Twitter can't ship new product.

[1] http://haveuheard.net/2015/08/kim-kardashian-how-much-money-...