In all fairness, the issues of economics as well as the overall controversial nature of abolishing slavery among the populace would have posed a lot of problems as well, so the founding fathers were being pragmatic to ensure the survival of their republic, lest they just decide to emulate France and reduce it to a game of Purge.
Doing the wrong thing for pragatism is still doing the wrong thing.
“...were being pragmatic...”
I asked a pastor once why did God “allow” people to have multiple wives, slavery, etc. - all sorts of stuff that went against the Ten Commandments.
I can’t remember the exact answer - but there were other things that were even more important for his people to get right first. Like getting rid of idolatry for example. And getting the BIG things right will lead to getting the other things right.