Curse launcher seems as if the overriding "theme" or "intent" was to turn minecraft into one big EASY BUTTON.
And quite honestly, that's exactly what it is. I made my own modpack the other day, and it was as easy as browsing a list and clicking "Install", then when I was done, just click "Play". So it would seem they've achieved that goal already.
The problem with "Curse and FTB partnership" is... the two are polar opposites!! Modded minecrafters are those players who enjoy tinkering and adjusting things... that's why we play modded and not vanilla!!!
I just don't think the two ideas mesh very well. Curse is "Easy Button", or "Modded Minecraft For Dummies", basically... while FTB is more like a 1970's teenager working on his 4-barrel carburetor in his Camaro Z-28... hands-on, get under the hood and get oil and grease under the fingernails... Curse is the 2016 Automotive Diagnostics Computer, just plug in and it will tell you what's wrong and which component to replace. LOL
IMO obv, your opinions may differ.