It's not that they can't; it's that they don't care. Airbnb has a great engineering team who could definitely setup a more secure way to do this.
The issue is that they only do things that will make them money. Until a lot of customers complain and hurts customer acquisition or revenues, they're not going to change it.
This is exactly the MVP / "lean startup" approach: do the absolute minimum. It's a smart way to deploy capital. But customers of these kinds of companies should be careful but they're usually complete products (by design) and may have sharp corners.
I normally stay away from buying anything from startups for this reason.
By definition they can not possibly be a great engineering team if they demonstrate that they are completely and totally incompetent like this. "I don't care about doing important things correctly" is a statement of incompetence.
The issue is that they only do things that will make them money. Until a lot of customers complain and hurts customer acquisition or revenues, they're not going to change it.
This is exactly the MVP / "lean startup" approach: do the absolute minimum. It's a smart way to deploy capital. But customers of these kinds of companies should be careful but they're usually complete products (by design) and may have sharp corners.
I normally stay away from buying anything from startups for this reason.