Why is it so common for people to say that? Staying at home for the rest of your lives could be bad, no sunlight, means no energy, and no energy means no inspiration. Nowadays, we do have the internet, and basically everything is in there, but what harm can a breath of fresh air do to you? Let it refresh you, and take time to appreciate what is around you.
Get in touch with nature, visit a local coffee shop, take your kids for a walk, drive around Las Vegas if you want. An idea can come at any moment, you could just be sitting at the park bench and see a vandalized tree, and it brings you back to a moment in your life you have forgotten. Maybe even if you overhear a conversation in the mall (I'm not telling you to go around and listen to other people's conversation), it could strike up an idea for a book!
Example 1:
Girl 1: Hey, what are we going to do about that science project?
Girl 2: Oh you mean the one about Blastocysts?
Girl 1: Yeah.
You: (Hmm.. wonder what that is)
You: *Gets home, searches it up on google, becomes highly interested, comes up with an idea for a new story based on Blastocysts.
Example 2 (without the whole overhearing part):
You: *Skipping down the road, trips on a rock, sees a squirrel far ahead, stands up, sees a funny looking formation on tree. (Hmm... That will be a good symbol for a long lost civilization)
Me: Congratulations! You just found a good idea you could build on!
My exact point is that, if you found yourself dreading to find an idea or inspiration, and you found yourself staying at home all through those times, try taking a walk anywhere. An idea, or inspiration can come up at any time. I am not saying that staying at home is bad, but if you really do find yourself in that kind of situation, TAKE A HIKE!