Miners tend to keep whatever coins they think will increase in value, and sell when they see the coin going sideways or down. Botnet owners have little of no overhead, so they just dump like mad. There is absolutely no positive aspect to having botnets on your coin.
1. I would like to see actual evidence of this as opposed to people just stating it. Is there any?
Theory strongly says that it is irrelevant, given perfect markets (which in the case of Monero actually is true!).
People earn in what they happen to get, and save in what they want. If these two coins do not coincide, they make a conversion between earning and saving.
Risto I think you missed the point. Botnets have an order-of-magnitude or more lower costs, thus this lower cost basis means they can sell at lower prices, thus they drive the price of the coin down if they are too much of the float (which I theorize could impact the exponential share of the distribution and growth curve).
While the debasement rates are high, the price of the coin is modulated significantly by the cost of mining.
Thus for two reasons botnets are not a problem in the long-term, but they can
destroyhurt a coin early on (when the long-term growth curve is being established and perhaps set in stone).
1. The difficulty eventually rises such that either the demand for botnets drives their prices up to parity with rented hardware or botnets fade as a significant % of the hashrate.
2. Debasement rates slow so the price of the coin is less modulated by the cost of mining.