A hard fork means your BTC would now be in both blockchains; but it is simple common sense that one of the two ledger must be invalidated in order that bitcoin is to be trusted - and survive. If the two forks last for years and I have my UTXO (unspent coins) in both ledger, that means both ledgers have been compromised. One must die off! Or one becomes the alt coin.       

There is no "free lunch" - never! Any "free forked coins" must come with a risk; it is a matter of good judgment over bad or luck.

After a fork, there are double supply of coins with two blockchains. There is a greater propensity to have greater sell pressure at each blockchain. But the number of new buyers per blockchain is halved. So it means a 50% or more price re-evaluation per blockchain - at USD 3000.