I did tell her that she should tip them(especially UberX) because they sometimes make less than minimum wage. She's mostly taking Uber in NYC so she probably believes the lies that Uber Driver's make 90k of pure profit every year.
Okay cool, it's really just basic math, I best try to explain it like this
We only make a percentage of each fare (as Uber take their cut) and then we still have normal expenses such as gas, wear and tear, etc.
I take an easy example, say a $10 fare, and let them know Uber takes $1 for a SRF (Safe Rider Fee) they then take another 25% after the $1, so 75% of $9 which equals out to us taking $6.75 (if we are lucky, I know the percentages can go higher than 25% for smaller fares). Then we need to calculate the time it took to get to the customer, the time it took to drop them off, and the time we spent waiting for a call (so they don't think, Hey you drove me 10 min and made $5 that's pretty good, 6 of those in an hour and you made $30/hr, which is what people who don't understand the system will think).
So really, on a $10 far we take home $6.75 (less gas, so maybe less $1.75 at the least) so that's $5 on a $10 fare. If we snag two of those in an hour we are taking in $10 (less the wear and tear costs). So basically, about minimum wage. If we're lucky.