Sellers Won't Tell You About Recalls
Private party sellers may be unaware of any recalls for the vehicle. Or they may have discounted its importance. Or they may think that it would be a negative to admit the vehicle has a recall. In fact, recalls are announced almost every week. Lots of vehicles have recalls. It's not uncommon. It is, however, risky to ignore them. You'll have to look up the recalls for a car you're considering on your own.
A dealer also may be reluctant to bring up recalls. Especially if it is a dealer which is not franchised with the manufacturer of the vehicle, for example, a used Ford for sale at a Dodge dealership or independent dealership. This is because they wouldn't be reimbursed for the repair. Even franchised dealers may take the approach that if you'll buy the vehicle without requesting the repair, that's less expense they've put into the sale.
It's your responsibility to know about recalls on your vehicle. Finding recalls is free. Fixing recalls is free. It's important enough that the Federal government has passed laws to make sure you're covered. There's no reason not to get them fixed.