The tube fulfils a purpose, however unpleasant it may be at times. Buses though are something else altogether. Horrible and slaves to traffic congestion. I get free tube and bus due to my partner working for TFL, but I still walk most places less than 3 or 4 miles apart because I find it far more preferable and enjoyable. I have no idea why anyone would choose to pay to travel short distances in London when they could easily walk or cycle.
I guess as the population increases the passenger numbers will increase. I know that doesn't reflect the bus score but maybe over time that will also balance out. Sadly, I fear the more buses they cut, the more they will use it as justification to make further cuts. But then I've already pretty much said I hate buses and don't use them... so what do I know?