Currently most altcoin purchases have to go through either BTC or ETH, once there are more direct options for purchase, this unbalanced stranglehold will dissipate.
One company looking at bringing in the larger non-crypto public via their payments platform is MONACO and part of their premise will negate the direct purchase of BTC/ETH before you are able to buy altcoins.
MONACO App and Card is aimed at bridging several gaps that are currently impeding public take-up of cryptocurrency, (Costs, ease of use etc) being some.