a currency serves whatever purpose it's user's determine.
If you want it only to play pump and dump on a virtual stock market then that is it's use.
If no one uses it for anything then it dies.
Thus 99% percent of all altcoins die out in a few months from launch.
Well the chance of an alternative currency reaching the level of adoption of USD is exceedingly thin so it is to be expected that most attempts to do so will fail.
On the other hand, altcoins aren't a threat to btc being seen as legitimate by the public. The threat is the idea the general public has about the legitimacy and safety of using cryptocurrency in general, which is not solved by making out all altcoins to be a scam.
They don't distinguish between various cryptos. To them it's all fake money so going around talking shit about altcoins because you think they will detract from the value of your bitcoins isn't really helping your cause.
The very same features that make altcoins seem like a scam to certain holders of btc exist for btc and btc is therefore regarded as a scam by the general public. The argument that it is somehow "better" is not valid in any regard. It actually has a energy wasting feature that is not desirable that is not found in newer types of cryptocurrency.
By fail I meant, nobody mining or using them aside from the maker, his few friends and some fool who still believes it's not over. If an altcoin could gain the level of Litecoin, I'd consider it super successful.
Don't twist my words: I said 99% altcoins are crap. You see 100%-99%=1%. That's the percent of all legitimate coins that exist and still function comparing to all those created.
I'm only talking crap about altcoins due to the fact that the majority (90-99%) are poor copies of either Litecoin or Bitcoin. Most of them offer no benefit except for the maker: the possibility of him becoming rich if his coin managed to stand the tests of the community. Look around: coins are being created every day, yet only a few actually are being used.
Regarding the fact they will detract from Bitcoin: not really, it didn't even cross my mind that one of those failures could ever influence Bitcoin in any way. Aside from those, any useful coins that introduce new functional features are welcome and some healthy rivalry is always a good thing.