Ok, here comes my noob opinion again.
I decided to roughly check my hoard of coins on Polo and I'm happy to say that I think 95% of them are higher than the initial buy in (altcoin/btc ratio). No, it is not to boast or what. I just realized that if you talk about "store of value", altcoins can also do the same! Indirectly, of course.
You might be asking, "Crazy guy, what are you blabbering about????"
Well, do remember that altcoins are paired to bitcoins i.e. altcoin/bitcoin ratio. If bitcoin and altcoins were increasing at the same percentage rate, the ratio would be the same. Say bitcoin is USD 1000 and altcoin/bitcoin pair is 0.001 (i.e. USD 1) a few weeks ago. Ok, take the price of BTC now - USD 1800. If the ratio was the same 0.001 (sat), the price of the altcoin is actually USD 1.8!!!
That means that with BTC's graph going upwards, altcoins just have to be at a plateau to enjoy the same gains. However, altcoins trend is also up!!! Meaning to say, in general, altcoins are gaining more than bitcoin!
Here's an example of one of my coin that is not moving much. Vericoin, bought on 18/4/2017 at 0.00006937. Now it is 0.00007314. Minimal gain right? No! On 18/4/2017, bitcoin was about USD 1265 when I bought vericoin, say 1000 coins. So that would be Vericoin buy price = USD 1265 x 0.00006937 x 1000 coins= USD 87.75
Now, bitcoin is USD 1800 which makes vericoin USD 1800 x 0.00007314 x 1000 coins= USD 131.6!!!!
Now, imagine those coins that has increase hundreds of percentage points when you first bought in.
Which one has a "temporarily" better store of value?
Of course, this is talking about BTC that is constantly on a rising trend and altcoins that doesn't crash and burn.
So what do you guys think? Am I thinking right or am I just plain crazy?

simply looking at BTC ratio means nothing. You have to record the USD\unit value at the moment of purchase to truly appreciate the gain from altcoins. most of the sea of red for alt coins are from btc rising, not alt coins crashing. but if bitcoins crash altcoins will most probably too