That's not what anybody is saying, and it's disingenuous to say that it is.
This study shouldn't be any great shock to anybody; that life is more complicated than a single cause for something. Some people are fat because they live a fat lifestyle. Some are fat because of their genetic makeup. Some are fat for a combination of them. Some people will have to put more effort into staying thin than others. This study suggests that these microbes are one factor.
The OP is making a statement that you completely confirmed: people are easily willing to bash and shame others. The second sentence of your post is the perfect example of using the worst possible scenario to describe everybody who exhibits a particular "fault". So tell me, what is the line of demarcation? Where is the fat line? What weight is 1lb more than the normal reasonable person and defines the lazy slovenly glutton you describe?
What about smokers? Do they suck as people too? Drinkers? What about people who curse? Are religious fanatics ok (that could go either way with you, I'd guess)? Sex addicts? How about people who are thin but can't run very fast? Are they lazy, too? Tell us, how are all of these people failures, too? And what about people with more or less intelligence: are the more intellectual people simply harder workers and the less intelligent just lazy?
Hmm, how about beautiful people vs the rest of us?
Are you perfect? And if not, is it because you're lazy?