To my knowledge the transaction fees is actually a reward for the mining computers for successfully helping us create a block on the block chain.With such low fees wouldnt miners be discouraged to do so i.e. wouldn't mining become less profitable.
Also bitcoin can never become proof of stake unlike other coins,so where does this leave us ?
Mining is more profitable when there are high fees, because blocks are always filled with transactions and the average fee rates are a lot higher. It doesn't necessarily mean that the network becomes insecure; sure it becomes relatively less secure, because certain miners find it unprofitable to mine but it doesn't make for an insecure network.
The transaction fee is a function of many factors, the most important variable at play is the transaction volume in terms of size. It hasn't been that high since the peak a few months ago and you can get away with much lower fees if you want a reasonably fast confirmation.