They invest a bit in the initial development then call it a day. Another example is the chatbots fad: after the technology implementation there's almost no energy for actually training those bots, so you as user are served with a fancy and overpriced menu system.
Which is why we need user-bots, that represent their clients interest with the same emotionless, ceaseless interest as a cooperation would represent its interests.
We're guilty of this, despite caring about the product and the users. It's hard to focus on maintenance and deep iteration when there's more critical (and cool) functionality to chase. Not to mention that iterative UX improvements have the same problem as negative results in academia - it's hard to get people excited about it.
