No one would directly attempt to be evil, it'd just turn out that way.
“The truly terrible thing is that everybody has their reasons.” ― Jean Renoir
There are lots of other sites competing for attention, and to sacrifice a good UX would be shortsighted, especially with all the “FB is dead” comments people have been making the last few years.
"Lard it up with debt, fire down to a skeleton-crew and stop all maintenance" sounds bad, like you're killing the company or something. "Unlocking value", hey, doesn't that sound better?
Similarly, "Let's get rich creating the second-coming of AOL by building a tacky nextgen panopticon" doesn't sound that great. "Creating a community of technical greats to bring people together and foster blah blah blah", while a completely bullshit nothing-statement, seems to shift focus off of the surveillance capitalism. For a bit.
Eventually, though, if you make your living sniffing other peoples' panties, eventually they notice and they take measures to limit your access to their laundry. FB and Google are both blocked entirely by IP at my gateway (along with a bunch of other surveillance shops), and the internet at home is so much nicer than what I see other people putting up with.
Really? Especially a FB PM you mean? Because PMs otherwise have been known to use exactly such techniques and worse:
Some low level PM was tasked with optimizing time-on-site. They had some negative user feedback, but it didn't show up in their low sample UR and segmented rollout. Since they had good results in their primary success metrics and the secondary metrics did not tell a consistent story, they rolled it out to 100%. Any negative feedback from there was chalked up to change aversion among a small segment of users.
See the Sean Parker interview: https://www.axios.com/sean-parker-unloads-on-facebook-god-on...
Increasing "time spent" means spreading out relevant posts. I'm sure that Facebook is tuned to optimize for some combination of "time spent without drop-off in engagement". This is a "Good" version of the algorithm because it nets them the most revenue, while still fulfilling the need for the larger user base.
It's milkshake marketing[0]. People don't want the most efficient method of content consumption. That's why most "feeds" are no longer chronological. People on Facebook want to scroll around, look at posts, comment on articles, like a few things, etc. for X minutes/day without seeing things they've seen before, and without seeing things that are boring.
The job-to-be-done isn't to consume a certain relevant piece of content, it's to waste time and not get too bored.
[0] https://hbswk.hbs.edu/item/clay-christensens-milkshake-marke...
The thing to realize is that there's not actually a functional difference between that and the "numbers-driven" guy you describe. Evil isn't just the sadistic maniac; it's the affable businessman who doesn't care, doesn't even consider, whether his product helps people or hurts them, so long as it maximizes profit.
Someone else posted an interview with the former president of Facebook, and it's pretty enlightening: https://www.axios.com/sean-parker-unloads-on-facebook-god-on...
