It's the simple urge every website must try to fend off: the quick money. If you can spend twenty minutes to make some image/GIF-based page pandering to the crowd and make more money than a thoughtful article, why not do that once in a while? Buzzfeed is making money for the very same reason. As sites -and their expenses- grow they will probably cash in more as it is just so much easier from a business perspective.
I understand the motivations that exist to do it, you would think though that certain publications would realize that the power of their brand is contingent on not chasing such things. I will say that I've always been very impressed with The Atlantic (on large) regarding the integrity of their content. There are a number of sites that I think do well to steer clear of such trappings but I bet the power of Buzzfeed, the allure of "traffic" is always there tugging at them. Someone needs to create a site, an aggregator that will never succumb to such temptations... cough, that would be great double-cough, a sort of hub of information if you will.
Maybe it's too easy to think of a site as a complete thing which is aware of its integrity. Instead I think these problems are often due to poor (= greedy) management or financial problems. So while most of the Times' hard working people probably realize that their less thoughtful content is more valued by the business, they often aren't in the position to change the attitude towards content. It takes good values at the higher levels of the hierarchy, which are often the people dealing with the money. And they often want to see that money increased. Not always though, some sites cough are run with the intent to create valuable information that works in the long run. I can't remember what site that was again... mk, would you know of any?
I'd rather burn the place the place to the ground than do something that I didn't think was worthwhile. I'm not saying that buzzfeed et al., aren't perfectly legitimate, but the world has plenty of that. Money is money. If you have more you have more. Other considerations can trump that.