My experience so far, made an account just to detail this, so take it for what it's worth. If you want to skip the story, i'll add a spacer for you all to pick up to my summary.
Download feed the beast launcher to do what the name entails, launch mods. I scroll through the ui which only took me a few minutes to learn, wasn't too complicated. Begin reading about mods and packs that i have never even heard of, so many cool things! My friends have started a mage quest server and want me to join them, awesome it works! Play on the server a few weeks enjoying these cool mods, Blood magic and necromancy being my favorites, going for a dark wizard vibe you see. A few weeks pass and i decide to play some more minecraft away from home, on my laptop, so i boot it up and go to the feed the beast website, and click the big red download button, and i'm immediately greeted with an unfamiliar program called curse downloading, now from my experience with the ftb launcher i knew that curse was affiliated to to its logo being there, so i let the download continue. After downloading i'm introduced to a simple registration page, and i attempt to login with my minecraft credentials assuming that this is what a launcher needed to well, launch. Nope, i need to create an account for curse, strange i didn't need to do that on my main pc... I create an account and come across the strange thing, a list of games for my avatar, why would a list be here isn't this a minecraft mod launcher? I click skip because i don't need an avatar, I need to launch mage quest. I then spend the next few minutes randomly clicking around trying to figure out how to stop curse from telling me to find friends and after another 5 minutes, gave up and angrily browsed the forums seeing a few others just as unpleased as me. Eventually i found the real launcher hidden under the large red download button and downloaded it and came here to tell my story, and afterwards will go fill up my blood altar.
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So first let me be blunt, i don't really much care for the community, and i don't mean that in a mean way, nor do i mean that is in i dislike it. I mean that i'm not here for a community i'm here to download mods, that's the sole reason, so i don't check your website nor browse through news, i don't know your partnerships or plans either I use FTB as a place to download mods for minecraft, not a forum or group. Alright now to the real reasons for this post. From what i can tell with curse, it isn't meant to be a pure launcher, it's a social platform similar to steam, or if skype and origins had a baby, and they decided to stay with daddies color orange. And thats fine, it's your choice to release what you want, you developed it. But i don't want a social platform, i want a launcher, you can tell me all you want to disable these features but frankly... no? I'm not going to download it in the first place, i see nothing wrong with the current launcher, it's doing its job of launching my game, where in my time with curse i couldn't figure out how to get away from the social aspect.
It's obvious that people worked hard to create this, but you created something that a group of people (whether that group is a large or small one i don't know) don't want, a social platform that has the ability to launch games. And my guess is that this was the whole point of the project but i could be wrong.
My only 2 suggestions for you, are as follows. Don't scrap the old feed the beast launcher, which you'll probably do eventually anyway. Or create a barebones curse minecraft client that runs as nothing but a launcher doesn't launch on startup, and doesn't stay running unless you hound it down to terminate it, and doesn't require an internet connection. Call it curse mini maybe?
And my last few comments thoughts and points, 1 curse is to kid friendly, children make up a large portion of any minecraft group for sure, but don't build your launcher of of that, makes me feel like an idiot just clicking around in it.
2 and this has nothing to do with the launcher really, but mod devs are people that i don't know by name and that i'll never really acknowledge, sorry but it's the truth, your mod is fun, i'll play it, i'll enjoy it. But i won't pay for it, I won't donate, and i'm not going to remember your name when i've completed my fun on the server, the only 2 things that matter to me are a search bar, a download button and a delete button.
So this is my thoughts, take it as you will, it's your launcher your group and your brand, but i don't enjoy any of the content enough to run it off of a different social platform. That's what steam is for, and it usually features actual games.