Internet in full of very heavy websites which don’t only take a lot of time to load on your browser but also utilize a lot of resources of your computer.
Well, most of the bloggers these days, specially technology bloggers, own some latest powerful machines with new technology processors and high ram etc. They check their website on their computer / laptop, and once they find it extremely light and fast on it, they consider it to be globally acceptable for all their visitors.
Well I know most of the world is very advance now. Maybe my country and several 
One thing to note is, that ofcourse no blogger or webdeveloper builds or tries to build a bad website. So this is just a matter of overlooking probably non-productive portion of their traffic? because people from these countries don’t generate much income on their blog due to several reasons!
Some of the sites with their average post page sizes are as follows:
nabtron.com 262 kb
goshycab.com 1.23 mb
mashable.com 3.53 mb
I am not sure what’s heavy site or slow site as per your computer’s configuration and broadband speed, but this is still too high! as on my websites with 200-300 kb site, google tells me that I am still slower than 65% of the websites on the internet.
Honestly speaking, I am really glad that google included page load speed in their search engine ranking criteria this year! otherwise there have been many useless and so called fancy javascript and stuff going on on many websites!