Quote from: jwinterm on June 30, 2016, 09:29:50 PM

Security can be an illusion though. For instance, onename (I think) dropped namecoin because it had a high hashrate that was completely dominated by a single pool, f2pool i think. Same deal for huntercoin, which uses both sha and scrypt, but f2pool owns 99% of the hash on both algos I think (tho they've announced they're going to stop mining huntercoin soon).

I think myriadcoin has a nice approach of using five algos, sha and scrypt being merge mined, and the three GPU/CPU algos not. That way a single monster ASIC pool can't own the coin least. Unitus also has an interesting approach of using five algos all GPU/CPU and all merge mined.

Tl;dr - hashrate != security

It is true it should be as diverse as possible.
On the other hand the level of diversity is also subject to constant change.
"Security" remains an illusion in all areas of life if you think deeply about it, it's not possible to achieve a 100% security in anything. It's always a relative security. (same goes for btc, your 401k or your fiat $ ... or even your precious metal holdings)