Why do people int because they get paired with a bronze player?

Lately I've decided to play some ranked. I did my provisional way back in January and got placed in bronze 2, now Ive started playing ranked because I want to see how high I can get and what my actual skill level is. But,

You see, the problem is you get people who start inting because you are in bronze. The game I just played a Jarvan IV decided to give the enemy team 2 kills within the first 2 minutes because I was bronze. Then I was a decent game ended at 4/4/2 with the best vision score on the team.

I want to have fun while playing ranked, not get flamed at because of my rank, isn't this just like "Don't judge a book by it's cover".

How am I meant to rank up if people purposely int?

Anyway, the reason Im making this is to see what the community has to say about my experience. One more thing, I was at a 7 W: 5 L before I played that game with J4.

Thanks.