Ok, I'll bite. Before we have this discussion, it's important to point out that I'm not trying to change your mind on whether or not reparations should be made. I'm making the case that the IDEA of reparations is not a stupid one, and is actually worth talking about.
While there is no one living in the US who legally owned slaves, and there is no one living who has been a slave in the US, the repercussions of slavery reverberate today. As a result of a couple hundred years of black people being viewed as less than human, only useful as beasts of burden, the emancipation of the slaves and the abolition of slavery did not end oppression of black people. Racist policies and good old fashioned domestic terrorism effectively curbed the opportunities of black people in the US for more than a century after, making it incredibly difficult for them not only to get ahead themselves, but also to provide stability for their families.
The end result is that black kids were raised in a vicious cycle of poverty, stemming largely from the knowledge (gained through generations of frustration) that there is nothing they can do to make things better. Education exposed them to further knowledge of their plight, without providing any avenues out due to racist hiring policies. The very few who were able to escape this cycle were not raised with the tools necessary to perpetuate their wealth, and often ended up losing it.
While this situation has changed significantly in the past 50 years, and the ability for black people to grow and maintain wealth is increasing, there is still much further to go before they have true equal opportunity. In poorer areas, the only way out is still considered to be as a recording artist or athlete; entrepreneurship requires cash up front, and opportunities for seed money are still highly limited for african americans (very few of whom have rich friends or relatives who are willing to invest).
There is no doubt that there is a disparity of wealth, and that this disparity is directly linked to centuries of slavery followed by a century of outright oppression. It's also clear that the roots of that oppression have not been fully stamped out of our society, and the fear of that oppression is still very present in the black population. As such, black people are still held back, socially and financially. Reparations would be an effort to remedy this.