Why should houses be painted on the inside?

Paint helps protect drywall from damage, moisture/mold, and dirt. It also doesn't cost near what you quoted if you're willing to put a little sweat equity into the project.

The only paint that causes cancer is lead-based, which hasn't been produced in about fifty years. Even then, the only way you get cancer from it is literally by peeling it off your wall and eating it. Modern latex paint is perfectly safe and, in general, pretty limited on fumes. You can even get odorless paint if you struggle with fumes.

Paint in no way raises the price of a home unless you're building from scratch and are talking about the cost of materials. No appraiser says "this home has more/better paint then one that sold down the street- better slap on an extra $1500 on that value!" That's not how appraisal works. Like, at all. And that's coming from a realtor (hi!) who runs her comps using the same cost modeling as appraisers.

Thanks for playing. Better luck next time.

yes

Protects the drywall for one, from damage, moisture, etc. Say in a bathroom with a bath/shower, drywall would soak up moisture and be ruined. Mold, etc.

Protects the walls. But the cost wouldn't be anywhere near that if you bought the paint and did the work yourself, more like a few hundred dollars including paint, brushes and dropcloths. The "encourages cancer" is bs, and also the claims of environmental damage. But if you don't want to paint it, don't. My house is far from new although it was when we bought it, and many of my ceilings, and two spare rooms, have never been painted with no ill effects. But kitchen and bathrooms, including ceilings, are painted to protect from moisture and grease.

U seriously uninformed clueless uneducated about reality of owning a house.

Stop listening to bull manure from uneducated conspiracy ranting.

Both claims are bull manure.

Hopefully ur parents are educated enough to explain why.

Paint inside walls ceilings or expect DAMAGE to walls Ceilings and construction of said.

Unpainted ceilings walls lead to absorption of stinky smells, mold, bacteria etc.

Please don't vote for anything more than AGT until you get educated.

It is NOT just for looks. You have to paint it to protect the drywall. Bare dry wall will mold if it gets even a little bit damp.