The doubling (Claymore said "1.5 - 2.0") of performance for 64-bit on Monero isn't enough by itself to mitigate botnets running at 32-bit.
If botnets are predominantly 32 bit (I don't know, but this claim is often made) then they are primarily older computers as well,
No it can also mean they are running on a 32-bit operating system
which is apparently still 50% of the universe.
I am in the Philippines and I go around to internet cafes and see a lot of newer computers running 32-bit Windows 7 and they are all loaded up with crapware and probably malware too. You do realize that 50 million people here are mostly accessing the internet via netcafes and not their own computers at home. Ditto Indonesia, etc..
And those Asian gaming machines might be running 64-bit and are newer hardware according to the steam survey I cited (and according to the sources I cited are available for 1000 computers for $15).
I don't doubt there are some botnets that target higher end gaming computers, but we don't have numbers. The article cited prices "per 1000" but we don't know how much that can scale. 10K computers for example, would only serve to further secure the network, not attack it.
You ignored my main point which is the 50% attack but rather disproportionate concentration of the ownership of the coin.
EDIT: There is another factor I forgot. Since the botnet has to evade detection it will run at a lower duty cycle, only mine when the computer is even turned on, and suspend or slow down mining while the computer is in use. This likely reduces efficiency over an intentional miner by at least a factor of 2, but perhaps 5 or more (if the computer is powered down a lot).
When you are buying them for $15 per 1000, even running on only 1 core and efficiency is not enough to cause them to not get coins too cheaply.
Without further data I remain unconvinced that botnets are frequently high end systems with good GPUs. And of course if they are then the whole argument of GPU mining being GPU-resistant is completely wrong. Even then the size distribution matters a lot.
I've noticed you are a person who ignores all threats until they are proven beyond any doubt. You don't like to entertain any possibilities that would cause you to make the conclusion that Monero is flawed.
How much effort have you done to investigate the botnets?
How much effort have you applied to investigating my points about your proof-of-work?
Or maybe...you are just making excuses.