What Mizhara says. That being said, most MMO mechanics are designed with the same idea in mind. Making things super grind heavy for example is also all about exploiting addictive tendencies. MMO developers want players to stick around and pay for subscriptions, so the devs tend to incorporate time-wasting activities with a carrot always dangling over the next little hill in order to keep their customers hooked.
Hell, EVE was doing this even before these login events. Skill queue caps were the original means. Similar idea: By making people have shorter queues, they'd need to log in to update them. Once logged in, they might play more. Once playing more, they might subscribe, and subscription means money.
It's not necessarily bad by itself, mind. But it is designed for that purpose, whether or not you see it as a problem. Same thing with daily quests, or BD's daily logins, or the Agency events, etc. And it can be an issue when you start feeling forced to do it because the rewards are sweet enough (that's the addiction part. You might not want to log in, but oh there's that reward and I really should get it. This is especially prevalent with daily quests. You quickly come to despise them... but you feel obliged to do them anyway). But what I see it more as a sign of is EVE drifting away from its sandbox nature. Sandboxes tend to encourage people to login by giving people the tools to create their own content. Constant content infusion (always an Agency event around the corner, ever more new ships, etc) and login tricks like reward weekends and so on make EVE feel like it's looking to linear games for inspiration. That's a little concerning - though, mind, of all the shit CCP has been doing, minor marketing things like this are probably the least egregious to me.