Its market cap is 60% fake.
It has a huge premine. Anyone buying it and holding it will sustain long term losses due to inflation. Since all the tokens kept by ripple labs will be eventually dumped on the market, ripple's value will decrease 2.5 times if new money doesn't enter its market.
It is highly centralized. Ripple labs is developing a product to replace the swift system but that can be done by Erc20 tokens or Bitcoin itself. So, I don't see any reason to have a specific crypto just so that it is used by banks.
I think it's due to the fact that it negates some of the interesting aspects of blockchain. Ripple is premined meaning the founders dictate when to give out some of the ripples and also considering the fact that it is centralised only increase the hatred.
Concerning the big market cap. You should know the logic behind this. Market cap is calculated by multiplying circulating supply by the current price. Now ripple has a circulating supply of over 39 billion XRP which is the main factor for its high market cap.
The lesser price also allow users to buy in multiples
I'd agree with @zoneboy and just add that it is a proprietary token and most of the value of ripple is based on trusting Ripple Labs. Trusting a centralized authority running an altcoin's network is not the common mindset for cryptocurrency enthusiasts.