well it is not reducing the total supply just affecting how mining it occurs. the dev wants people to be able to mine this coin for a long time. and wants this coin to be long term. i beleive it is also a drastic change. i suggested the block time be switched to 60 seconds to help with larger miners working on stale work. the block reward im not sure how keen i am on it.
Well, these changes will definitely make mining last awhile - probably 60 years or more. Kindof ridiculous in my opinion, no one can even begin to predict what the crypto-currency world might be like 3 years from now, let alone over half a century. Just think - 60 years ago from today we didn't even have color TV.
The existing block reward of 1,000 coins is a reasonable length of time, with roughly 1,388 days of mining (almost 4 years). Implement some block halving intervals in there and you could easily stretch it out.
As I said earlier, I have seen others use this strategy in an attempt to inflate the price. It sounds logical that reducing the mining rewards will eliminate alot of mine-and-dumping, which is often blamed for a drop in price. In reality, what causes the price to drop isn't miners dumping, but a lack of confidence in the coin in general, which equates to a lack of buyers. Miners won't dump if they are confident the price will go up.
Such a drastic reduction in mining rewards, and increased block time (and therefore slower transaction confirmation times) will be hurtful to the value of this coin. The network will slow to a crawl when the new block reward is put in place - no one is going to mine this coin for 1/20th of the value they are getting now, unless of course the price goes up by 20x to compensate (unlikely, without other efforts than the new code base). Just my humble opinion.
It's pretty obvious that one or more miners are dumping their coins every hour, every day. These miners don't care about what is coming for the coin to sell at such low prices. Reducing block reward will stop that.