This kind of decision is breaking trust between you and me. You're screwing all peoples who put money into the coins and who keep working on it. You'll make peoples losing money, and you'll break more trust.
Miners are mining because of the market price short-medium-long term. They mine profitable coins or coins they trust. Miners are selling to guys like me.
You say miners are mining because of market price. That is false. I mine because i see a future in PRT, just solely because of price. You state you are an investor, so how can you say what miners are mining for?
Also i see no reason thsi would make an investor lose trust? Yes maybe the "unintended" block change would fall under this "lose trust" category, however the change is NOT, i repeat...NOT increasing PRT count, we are just shortening the time frame of which the final coin will be distributed out.
This in turn means that the final coin will be avaliable to the public at a shorter time.
As stated by matauc, changing the block reward has occurred on BIG coins before such as LTC and we did not see a severe drop on price. I personally do not see a reason why a price drop would occur.
The coin holding community of PRT is resiliant to selling their stashes at current prices, which means ones who want to BUY PRT is stuck continuiously increasing their buy price until one of the miners decides to sell it.
I sell anywhere from 10k-30k REGARDLESS of price for every 100k coins i mine. The reason being i want people to BUY the coin and i want the markets to continuiously change on pricing. It gives me a sense of security on more people having coins to go around.
On a small side note, selling 100 PRT increments for a total of 30k is VERY time consuming and demanding. I specifically dig through the exchanges to find specific buyers of this coin to sell my PRT - i dont want one user to potentially gain the 30k that im distributing out.