simple translation:
1. many altcoins are pump and dumps
2. many altcoins are premined
3. many altcoins are made not by many people, but by a single person
4. many altcoins us the same code, with miner tweaks
5. many altcoins have no utility, but as soon as the coindev sells his premine, he no longer cares
6. most importantly. although altcoin devs grab other peoples bitcoin and hand out worthless alts. it does not damage bitcoin.. sooner or later the coindevs will sell their bitcoin. (keeping it in circulation)
summary:
altcoins are equivalent to 'penny stocks' they have no usefulness, but are a quick boom and bust 99% risk to trade with
DO NOT use altcoins as a store of wealth/value
Best translation ever.
And one hell of a disclaimer too.