Even though Altcoins cannot mimic what they did during the late 2017 they are still somehow mirroring Bitcoin's movements the only difference is they aren't as high or as near in their ATHs when they are moving along with Bitcoin. The only thing I see why the bear market that was triggered after the 2017 bull run cause some kind of FUD that made a lot of demand go away from Altcoins, most people who entered the market during the bull market are looking for the "Next Bitcoin" that's why they resorted in looking at Altcoins the problem is all the newbies who bought them all lose their money because of a bad trade. This cause a lot of demand going out from the market and all what is left are still the ones trusting BTC and the crypto industry.