I once missed a plane back from Berlin and had no money for another one. This was just after the largesse of the early days of budget air travel had been reigned in – not long before, I'd simply been chucked free of charge on the next flight when I turned up after check-in had closed.
A couple on the train back into town gave me €20 and I called up an acquaintance who offered me a floor to sleep on. The next day I took the metro to Unter den Linden and went to the British Consulate, expecting, I think, to be taken into a wood-panelled office and politely told to fuck off. Instead, I was told irritably to fuck off by a woman sitting behind a screen made of toughened glass. In my case, all I had to do was make one humiliating call to my mum. I guess others would have had a long hitch hike ahead of them.
The general rule in this world, though, is that if you've always been poor, nobody will give a fuck about you, but if you were relatively rich until five minutes ago before coming a cropper as a result of your own stupidity, you'll be inundated by offers of support. As such, I suspect any Western tourist idiotic enough to run out of cash in Kenya would be kept in fairly good stead at the expense of local people (many of whom can only dream of going off galavanting around the world), until such a time as an article appears about them in the Daily Mail and a GoFundMe page is set up.