Note that deep down, miners wouldn't mind bigger blocks right now, as their income is still mainly block reward.  They are thinking after the next halving.  Sooner or later (bitcoin's fundamental design) fees will have to replace block reward.  That can only happen if transactions are scarce.  So transactions HAVE TO BE SCARCE FOR BITCOIN TO FUNCTION in the long run.
That was in the system since the beginning, but as long as there were big block rewards, people weren't thinking of that.  The last block halving has signalled the beginning of the end of that period when transactions were cheap.  Now, they have to become expensive to pay for PoW.