As explained above, transaction fees will pay the mining
*sigh*
Ok. I'll take it slower for you.
The current block reward is 25k$ @ 1k$/BTC. Currently, there are 100-600 transactions in a block.
That means, if we were to sustain the current network with transaction fees alone, each user would have to pay a transaction fee of 25k$/0.6k = 41.67$ per transaction. Would you pay that?
10$ sounds to me like a barely acceptable transaction fee. At 10$ per transaction, 10$*600 = 6k$ block reward. Would you mine for that at the current difficulty? Not everybody has free electricity.