I respect anyone's perspective on this market, but back it up with facts
Oh com'on, look who's talking
People will still hold BTC, but choose to transact in other coins, so how can these coins die? Tones anwer is - that the features that are adopted by the altcoins, the popular features will be added to BTC, hence making these altcoin absolete
Well, somehow I thought he would come up with something better than that
And it is not only that Bitcoin's development is slow as you correctly noted and as it should necessarily be given the role it plays as a store of value (which this Toney dude himself seems to admit), it is also maximalist's view that there is a state of perfection which can be achieved and nothing to achieve thereafter. Bitcoin still is and will likely always remain a work in progress, so there is not a single reason to think or believe that once Bitcoin adopts some feature from an altcoin, it will be like the end of the world for altcoins (and for Bitcoin too, for that matter)