Yes agreed that XRP is centralised one and its not a real crypto currency but we should not forget that they are running their network over the blockchain and it makes half of it!
Tron is establishing their own blockchain and can be making a platform for different ICO's. It might just turn out triumph in the future.
Just mentioning what i do think about them. I might be wrong as well.
If you think Ripple and Tron are scames, you should specify where you suspect scammy behaviours and the evidence (lack of code) - Ripple is used by banks for cross border payments and Tron will launch their own blockchain (Main Net Release) and seems to be rather another Ethereum competitor for ICOs.