For now, I agree ... but that could change in the distant future. We don't know it. My point was that e.g. if Ethereum (or any other altcoin that F2Pool doesn't support) manages to get 40-50% of BTC's market cap F2Pool could change their opinion and support Segwit to ensure BTC conserves its leadership. (At the moment ETH is on 20% of BTC's marketcap so it looks not completely impossible, although I wouldn't bet on it).