Since network power is largely determined by profitability, which is largely determined by difficulty, which is inversely proportional to combined proof-of-work of the network, I would think that the amount of proof-of-work will reach the same levels regardless of whether specialized mining is allowed or not;
For every person who mines on a CPU just for the heck of it, there's an equal and opposite professional miner who is discouraged by the increased difficulty. So while the identity of miners might be more diverse, the proof of work will be the same. However, to mine on a level technological playing field for Bitcoin will mean you have to invest in ASICs. Anyone who tries to attack Bitcoin without ASICs won't even get out of the door.
in that case, the specialized mining gains no advantage against botnets, because the botnets are still fighting against the same amount of proof-of-work, whether mining is specialized or not.
The point is that ASICs do *much* more work, leaving anyone who tries to mine without them at a massive disadvantage.
In these other "scrypt" coins, the decreased proof-of-work of the asics and gpus is just made-up-for by an increased amount of cpus. The bot-net still has the same amount of proof-of-work to fight against, which is mostly determined by the mining rewards and the value of the currency. Ultimately, the theory is that you have same proof-of-work, dictated by same factors of profitability, but distributed more widely.
No. To compete on a level playing field with miners, someone attacking Bitcoin has to invest in ASICs, otherwise they're at a massive technological disadvantage.
Yes, the total amount of proof of work will be the same in both cases. You won't have more mining because you don't need to invest in ASICs, you'll just have more casual miners and thus fewer professional miners.
If you really don't see it, consider two coins with exactly the same money spent on mining except one uses ASICs and one uses CPUs. Which one can you more easily attack with a bot net? Which one can you more easily attack with rented hardware?
Bitcoin got this right and people who don't understand security are mindlessly trying to fix what is not broken.