Why are median transaction fees so much higher now (in october 2017) than a year ago? Now that segwit transactions are consistently making up 10% of each block and the witness section is making up more than 6% of the block, I'm a little confused by why median transaction fees are still high. A year ago, there were about 230k transactions/day and now there are about 260k transactions/day - just a 13% increase. But fees are up 1400% since a year ago.

What's causing fees to remain high even tho we've increased capacity by 6% (and rising) and only have 13% more transactions? Are people still falling for bad fee prediction algorithms? Is there an increased demand for quickly-confirming transactions?
The relation between average transaction size and average transaction fee is not linear. 


  Are people still falling for bad fee prediction algorithms?


There are no good prediction algorithms here. Think about 110 people waiting for  a bus, but the bus has only 100 seats. 


  Is there an increased demand for quickly-confirming transactions?


I don't think so. Most of users do not care at all about transaction fees while their capital grows.