It's just another game launcher to me. Like steam, gog, origin, battlenet, etc. It doesn't have any of the fancy profile options, forums, emojis, chat, etc that steam has. It's just a generic game launcher and they give away free games every week to try to get more users. But they're the developer of fortnite so they already have probably millions of users already since it's required to play that game on pc.
I have roughly 50 something games with them and I never even put my credit card in their system. I just log on once a week and claim the free games. Or like right now I log in once a day. I got world War z free from them earlier this year, I haven't tried it yet tho. I got gta5 from them early this year to and I have it installed but haven't played it yet.
I guess people complain because they are steam fans like Xbox and Playstation fans complain and try to maintain some loyalty? I actually add all my games to steam with the "add a non steam game to your library", then I make the shortcut the link to the game and it launches fine from steam. I'm currently playing starcraft2 on steam. I launch the steam link app from my living room on my nvidia shield, it connects to my pc, I launch starcraft 2, that link launched the battlenet launcher and then I'm playing sc2 through steam. I can do the same with games from epic games. I got Ghostbusters remastered free through epic on Halloween, installed it, added it as a non steam game and now I play it in my living room thru the steam app to. I only played it for a few mins to make sure it worked.
I'm not sure why people wouldn't want free games just because it's on a different game launcher. I know they got crap for different exclusives or timed exclusive deals but it all plays on pc so I don't get why people really care. 🤔