How does "new money"'s perception of the coin change if the inflation period is long? I mean, what benefits are there in the long inflation period for investors? How is growing economy of the coin dependent on the length of the inflation period?
Nobody loves inflation, but few people regard it as a horrendous evil to be avoided at any cost. Normal people do not expect that a hoard of cash will keep its value, much less grow more valuable, by itself, over time. And, for the good of the economy, they shouldn't "invest" in cash or other "dead" assets: they should use their intelligence to choose productive enterprises, and invest in them.
Cryptocurrencies were meant to be means of payment; their repurposing as long-term investment has always been criticized by economists.
My view is more practical. I believe it is a good idea to have an uninflatable store of value (this is the original Bitcoin thinking). But if I am faced with a choice to buy into a coin whose community is growing and consists of people willing to store their savings in this inflatable currency, or a coin whose community is eager to unload their stash to the next generation at greatly higher prices and live well off the proceeds, I go with the former. That I
am currently part of the latter also, should not be a distraction.
Bitcoin was the best choice in 2010-2013. Now I have been the early promoter of this thinking, and the coin I believe best suits it, Monero. The amount of actual attacks speaks about that it is taken seriously.