I don't think redemption is worthless. It's presence forces a company into action. VCs are investors -- they aren't your friend. They need a way out of a company where there is no other exit in sight. Normally, redemption gets reset on each succeeding round of financing, restarting the clock. But, venture investments have shelf-lives and born-on dates. When they start to get stale (no new investment round and no exit in sight), VC's get itchy. Note that a VC can voluntarily renegotiate the redemption if they believe that they can do better by waiting. But, they hold the cards on this one.

Think of redemption as a vaccine. The problem it solves isn't extinct. It still exists, and redemption rights are the anti-bodies that fight the problem.