1st day driving & of my 14 rides in 5 hours, only 1 pax tipped!

I’m a good and safe deover with perfect driving record. Furthermore I’m polite and asked every pax how their day is going, if they have enough leg room, if the AC temperature is okay, etc. Then I left it up to them if they seemed to want to chat. Very few did. Most preferred being in their phones. I’m in San Francisco Bay Area. 2/3 of my rides tonight were in Oakland. Of the 14 rides only a 30s white couple tipped me. I made $140 in 5 hours. At my regular Mon-Fri day job I make $340 per day and only work 6-7 hours. I’m not expecting the same kind of pay as my day job, but was hoping half of the people would tip and here I am feeling guilty when I haven’t tipped someone for pouring a coffee for me. There were 2 rides which I drove 20 miles each - one of them dozed off the whole time and the other was chatty with me so I don’t get it. I’m not disappointed in Uber but quite disappointed in passengers.