Removing loopholes, reducing the kinds of things that can be claimed without solid proof (or likelihood of needing to be proved, or complicated to prove), reducing the amount of paperwork that can create loopholes, etc. is part of simplifying.
Removing personal deductions, a simple 1-step calculation, is not simplifying.
And reducing tax rates is not necessary to simplify taxes. A graduated income tax is very simple.
Think about it harder. Don't be intellectually lazy and just jump to cutting certain taxes because it would be "simpler". Unless that's your goal.