Holding altcoins may be one of the ways how to get rich in a long term (because that surely won't happen overnight).
And the truth is, that there are many alt coins on the market which have increased their value in hundreds of % recently. If you invest in alts at the right moment and cash out them at another right moment, you can make a significant amount of coins.
long term? no way!
altcoins are only good for a short term investment (except 1 or 2 of them). if you buy them in the hope that for example in a year or two they are going to be as big as bitcoin, then i have to tell you now that you are wasting your time and money and you could have made lots more profit by short term investing in altcoins and dumping them on pumps to make lots more bitcoin in return.
I can't think of a single coin worth holding long term other than bitcoin, not even 1 or 2 altcoins... Ethereum? Huge risk, will hard fork, we will see a big mess again eventually.
XMR? Not sure, the coin is yet to show how to properly scale without centralizing the nodes.
What else is there?
With a long term, I mean year or two in maximum. And no, I don't expect any altcoin to be at bitcoin's level (in absolute numbers) after one year, but it would be ingnorant to think, that bitcoin is the only coin on the market which grows over time. If you choose wisely, your investment can grow in thousands of % withing one year.
I'll give you one particular example - on Jan 2016 you could buy Nexus (NXS) for 400 satoshi, after one year on Jan 2017, you could sell Nexus for 13 000 satoshi, it means it is 3150% growth. Comparing to bitcoin, on Jan 16 btc was $400 and Jan 17 btc was $1100. It's 175% growth.
Count with me. You have 400 bucks (to make the calculation more simple) and you invest them to bitcoin, or you can invest them to Nexus. Lets see what happens.
Jan 2016$400 = 1 btc
$400 = 1 btc = 250 000 NXS
Jan 20171 btc = $1100
250 000 NXS = 32.5 btc = $35 750
Bitcoin investment pure profit: 1100 - 400 =
$700Nexus investment pure profit: 35 750 - 400 =
$35 350What I wanted to say was, that absolute numbers don't matter when you want to invest, so altcoins can be as good long term investment as bitcoin or even better.