If this is a surprise, you did not do your due diligence. Paypal has acted this way for a decade for less risky items than BTC.
Ebay, ok. Paypal, wtf people?
To be fair, PayPal are subsidiaries to eBay, like vadoff and myself both stated, the CEO was initially for it. ("Comm error"? Nah.) And this is a harsh lesson against leaving large sums in PayPal. Get it moved as soon as possible.