It is manipulation, but according to statements by Brad Garlinghouse, Ripples CEO, it's about granting investors a sense of certainty that the market cannot suddenly be flooded by currency:

"We want to make sure that the Ripple Consensus Ledger is the most robust, and that XRP is the most liquid, and I think this is a very positive step towards that."

Given that most investors will not dig any deeper, I can see this hurting the immediate speculative value, but does not change Ripple(XRP) underlying utility or economic values.. If anything, it's a good time to buy.