There's a significant difference between having a house + a fence and an actual self-sustaining castle with its associated revenues.
Well, in a castle you have a keep (the lord's "house"), several utility buildings (stables, barracks, ...), and a wall with a gate. Now, you can also have a village or a little city around walls too so people houses do not burn down when invaded. However, the farms are out in the country yard.
Now, having stony castle or a woody one is just a matter of technology.
There's a lot more content that you get from the Stronghold vs. the house, so the Stronghold is a more exciting option from that perspective.
If you're talking gameplay wise, yes of course. I was just answering the "What purpose should the house have that the stronghold doesn't? And vice versa?"