Agree, I think its much better readability if we use curly brackets only if a loop or if() statement has more than 2 lines. I hate when people use brakets liket this thou:

for (int i = 1; i <= n; i++) {
     if (n % i == 0)
     	sum += i;
}

Better readable like this:

for (int i = 1; i <= n; i++)
{
     if (n % i == 0)
     	sum += i;
}