At least Ben Franklin had an abolitionist arc later in life. I don't think the intent of putting a makeshift keffiyeh is to desecrate the statue. The protesters are clearly trying to be respectful and win over "moderates" here!
The term founding fathers is an unfortunate one. It was a varied group of people with different beliefs and levels of participation. American history always makes it sound like one group of besties who hung out all the time and agreed on everything. I don't think that's what you or dirt were doing but I hear it a lot