The top players right now (besides Monero and LTC) are all scam coins (ETH, DASH, Ripple, et. al.). A centralized, banker and corporation funded coin like ETH or a system (backed by the same groups) such as Ripple can easily overthrow the Bitcoin market cap within a week.
I agree. I also thought about it. Even if one of this coins surpasses BTC in marketcap, their fiat (ETH), scam (DASH), centralised trusted (Ripple) nature will become evident sooner or later. Unlike you I also disrespect LTC since it's a copycat.