What could be the reasons behind this decision? Wouldn't it be better for mobiles to use pagination too, so less data is downloaded if someone decides to stop reading?
There is no room for pagination in mobile in my view. As a designer your task is to make the experience seamless, easy and hustle free.
Having pagination means that user has to press each page number or next page buttons. This can be quite hard on a small screen especially if you have more than 4-5 pages. Avarage thumb size is 72px making it quite hard to target small links and buttons. As research shows mobile internet not only on the go, but it doesn't mean that we need to make it hard for a person to use our service while they are. Metros, trains, cab rides are bumpy and small buttons make it harder to target them.
In my experience I really cant stand applications or websites where I have to tap the button about 2-3 times just because the menu item is so small and I kept missing it.
While continues scrolling is easy! It's impossible to make a mistake there all you have to do is move your finger/thumb up or down!
As an addition to Igor-G's answer.
In my opinion, the best way to solve the problem of
(1) not loading too much content at once and
you should lazy load the content.
To allow your users to get to the bottom of the page, you can just place a (preferably big) 'load more content' button to instantiate the lazy loading the first time. From then on you should lazy load the content with every scroll.
I absolutely hate websites that won't let me get to the footer..