>Journalists value the sensational over the factual, and work hard (true) to tight deadlines.
No, people do. There are tons of highly professional journalists who want to do good work and write important, well-crafted, accurate stories. Who were inspired to get into the field by Watergate. Who are constantly begging their bosses to do labor-intensive features.
The economic reality is that there are not enough people who want this enough to fund it, except barely at a handful of institutions like NYTimes. Good work takes time and manpower and it doesn't sell. If management is doing its job (maximize shareholder value) then it is doing everything it can to turn its paper into Buzzfeed.
There are thousands of journalists who left their dying papers because they couldn't stand it anymore. Thousands more who were simply laid off, or took buyouts because they saw that they were going to be laid off if they didn't. My dad is one of these. They'd want nothing more than to work at a real paper again, but there aren't really real papers anymore.
Being sloppy and fast is absolutely about service to the customer. With a daily publication deadline, you can generally take the time to do it right. But the readership (and therefore management) wants stories on the internet as quickly as possible. Of course they are going to be sloppy.
(I agree with all your complaints about TV news, because that's what it's always been. In print... that's what they were forced to become when the money became tight.)