Fees are always optional. Right now $0.25 will make a tx confirm in under 70 minutes (typical 225-byte tx, 40 sat/B: https://bitcoinfees.21.co). Solutions are being developed left & right to further reduce this: alts, segwit, block size increases (segwit2x, BCH 8MB blocks), payment channels, etc.

(Answer edited. Yes merchants care indirectly about fees.)