Every market goes through swings in sentiment. The only reason that the mined BTC coming to market, or retailers selling BTC, or anything else is an issue right now (as opposed to 14 months ago) is because sentiment is moving in the opposite direction. In late 2013, this was no issue at all because sentiment was on a massive upswing. Its the same sentiment cycle affecting all coins together, no manipulation required.
In my view, every day that BTC survives is a day that makes it stronger on the path toward a mainstream crypto-money. Investors then regular people will come more and more to believe in the security of the BTC block chain. Anecdotally, the amount of venture capital now looking in that direction is tremendous, and this investment will improve the utility of the network and ecosystem. In this context, volatility is a growing pain on the path to become mainstream. Volatility is not an innate property of any coin - it simply reflects the maturity of the market. We can't know for sure if BTC will be the one to get there first, but at this point, even deep into a bear market, there are no clear contenders close to rivalling BTC.
So I am not one to write off BTC just yet because of bear market. However there is still an opportunity for leadership change. If BTS or any other coin is to vie for this position, it must unambiguously demonstrate its added value to users and potential investors in the VC community, but there is a window of opportunity to prove this out before the growing network effects carve out all the secondary contenders.