The supermajority (perhaps not of the people, but of the supporters of various altcoins) believe that the initial emission period should be rather short, to "get rid" of the pesky "inflation", so that the coin can "start rising in value".

I believe they are hoping in vain, because the "new money" not yet invested, does not see such a coin as a very interesting investment and do not buy it. So instead of a rise, a fall in value is the result.

The only way around this is to grow the real economy of the coin big enough, before the declining emission really hits. This can hardly be achieved in 1 year, so a considerable longer time before half is emitted should be the case.