Yeah, to be fair, the Foundation books can be even harder to get into than Dune. The first two or three are just a series of short stories connected by a common thread. It's a sweeping epic tale of the fall and rise of Empires so you don't have a stable cast of characters or a central plot to carry you through the narrative.
If I was trying to get someone into sci-fi literature I might recommend they start with something more like early Heinlein ('Starship Troopers', 'Citizen of the Galaxy', 'Puppet Masters', etc.) or maybe 'Ender's Game', 'Rendezvous With Rama' or Kim Stanley Robinson's 'Red/Blue/Green Mars' trilogy.