I hate their usage of dark patterns to trick users into giving them access to their email contacts. I consider myself a fairly savvy user of the internet, and apparently I fell for it. (When I checked a while back, LinkedIn had access to my Gmail contacts despite my never intentionally giving them such.)

And as others mentioned, they send out emails that purposely look like some LinkedIn user has sent something to you specifically.

I think they're utter scumbags.

I really dislike their aggressive attempts to get new members to send out join requests to every person they've ever corresponded with on gmail. I've gotten many invitations from people whom I'm pretty sure had no idea that LinkedIn was going to scrape their contacts and spam everyone. This happens a couple times a year ever since like 2010? I haven't seen any other tech company do something similar. There is a lot of value in their network, but this is pretty obnoxious and basically dominates my impression of the tradeoffs they're willing to make

The biggest complaint I hear about LinkedIn is the amount of email the company sends users (not mail generated by other users, but mail generated by LinkedIn itself). It also seems to rather consistently ask to access your email contacts ("who do you know on LinkedIn?").

A few things off the top of my head.

The first thing that really put me off was when LinkedIn asked me to give them access to my Gmail account.

I don’t like their endorsement system. It asks my network to endorse me in things I’ve never mentioned I know. So the guy on your network thinks that he ought to endorse you out of courtesy and you end up with a list of a couple dozen things you are totally unaware of. How does this helps with anything?

Then there is the fact that pretty much everyone in there lies about their experience or their job titles. And I mean everyone, or at least everyone I happen to know. I get it, most people want to be perceived as more important than they are. But to me this whole situation seems ridiculous. And that leads to another problem. You can’t find any really interesting and engaging discussion because everyone is careful not to overstep any boundaries that might make them look unprofessional. Bottom line there is no community in there which makes the whole site much less useful.

Many aspects of their site are ridiculous. They hype up 'profile views' to try to get your to pay them to see a little more info about who viewed your profile. They encourage ridiculous endorsements that are completely meaningless. Etc.

I don't know if this is still the case, but around the time they IPO'd, I deleted my account as it had been worse than useless, but people I know mentioned I continued to show up as if I was still on the site.

Tons of recruiter spam and so on, not to mention the email dark patterns.

All "x site is the new resume" approaches are flawed, but at least GitHub-as-resume encourages publishing code and evaluating people by the code they've written and how they interact with open source projects. LinkedIn is good for cronyism and pretending that "n years at Company Inc." is particularly meaningful.

The completely pointless 'skills' sections, where anyone can add whatever skills they like to their profile. Oh, you're skilled in 'Data Center'? How utterly meaningless.