Yes I know. I file tax returns too.
The fact is that a glance at several consecutive years' tax returns can reveal a whole lot about a person's means/income/worth. It's possible he has a trillion dollars hidden under a mattress somewhere but more likely that a large percentage of his assets are earning him income.
Tax returns are NO ONES business except when getting a loan at a bank and YOU give access!! I am actually quite STUNNED no one has leaked them for money!!!