Please feel free to attack Monero if you are so confident in your assertion.
I have better things to spend my BTCs at than ruining blockchains. Remember the game theory assumptions that comprise Bitcoin's modus operandi do not really apply for altcoins.
The game theory behind Bitcoin says that one will not try to destroy the network because he himself will lose out while trying to do that. When it goes in altcoin battles or fiat (=government) vs whatever-coin, this is a different issue altogether.
You are absolutted right, thats why large players like rpietila has chosen Monero:
Yes, well, the market cap of each coin speaks for itself really as to what big money do on aggregate. MRO is playing at 1.5-4M and DRK is like 35-60M. It's like comparing the small league to the big league. And don't forget that some of the money on MRO (including my own) are on MRO as a hedge.