No offence, but with a headline like that, just proves what I've been saying.
It's all self awarding, self gratification. Anyone can enter what they like and anyone'll believe it.
you talking to me? 
OBVIOUSLY.
You're in marketing aren't you, so you must love the smell of your own sh!t and love to tell people how good that they think they are.
Like most of the professional world. Not that any of that would happen in der military.
Like any social media platform it has its weak areas, but if you're in a network of professional people then it's a good way of benefiting both in your job (improved networking) and in the search for your next potential job.
I work with IBM a lot. Given how that landscape can flex LinkedIn is essential in keeping up with who's doing what. You know the first thing most of their sales and marketing team will do when your email drops into their inbox is search for you on LinkedIn.
I don't understand why people in a job above minimum wage wouldn't be on LinkedIn - it maps professional relationships. If you don't see how that's useful then I would be suspicious that either you're an idiot or somewhere on the autistic scale and your talents lie elsewhere.
If your account gets hacked the best thing to do is sort it out and get it back straight. If you're in an industry where LinkedIn is in use the last thing you want someone to find if they look you up is a profile that's been hacked popping up in Google results. Even a deleted hacked profile will echo down the search results for months/years. Over-writing it with valid information is the best way of resolving that, not just shunning the location.
Treat it like any professional resource and only map the network around you who (as it says in the template invite) know and trust. This approach should resolve a lot of the problems people seem to be voicing.
Oh and unless you're desperate for work, make sure you 'I don't know' this person if you get invites from people who you don't know or random recruiters - when they get a certain number of these their account privileges get locked down, even if they're paying for their account.