Primecoin is already a success in breaking CC length records. https://bitcointalksearch.org/topic/xpm-primecoin-record-books-253409
It is useful already. Whether you care about it or not is irrelevant.
That's debateable. I'm sure there are world records for climbing the highest tree or eating the biggest cake in like 30 min. That doesn't make those records or actions useful.
The usefulness of a hoby is if people can have fund doing it. People look for record as a hobby long before Primecoin existed. Finding a CC with a new length record is like finding a new piece of jigsaw of our universe. Once you have discovered it it's your record forever. As a pastime primecion's usefulness is not debatable.
Here we go again. I think 98% people of the world don't think or know cryptocurrencies are useful. By your logic cryptocurrencies are useless?
Pretty much yeah. You don't think the masses are getting into BTC are you?
"Hey there's this digital currency, right now it's mined by ASICS (what), but you can buy a BTC for 100$!"
I don't believe in global acceptance of (alt)coins no, is that wrong