Well, they do aim to add pretty much all tabletop mechanics and equipment into the mod. And there is a lot of them missing from vanilla.
They don't just include mods though. Lots of them were actually build by someone from RT team for RT in the first place and then also released as standalone mods. While included mods are often heavily modifyed to work together as a whole and for ballance purposes.
And yeah, it does drive them crasy when mod is called a modpack or kitchensink mod. It makes people think that they can easily add / remove / modify mod parts or just use them with vanilla. Then all of those people go to support channel and start to bombard devs with angry questions why nothing works. It happens a lot actually.
It is a modpack though, the vast majority of the mods were originally seperate from Roguetech. I don't understand why this is a negative term. If anything proves this point, it's XLRP, since it's a lot of the same mods. It has a very "RogueTech, back in v1.2" feel. Only without the pirate equipment and clan stuff (it's goal is to be lore strict).
All of the extra mechs, are seperate mods.
The AIM lines system, is a seperate mod.
Panic System, is a seperate mod.
Mech Engineer is a seperate mod.
CBT piloting, heat and movement are seperate mods.
Wartech/Online mod was a serpate mod (now Roguetech only, unless you use an old verison).
And so on. These are just some of the most important ones.
But what you can't do is try to reverse engineer Roguetech to re-seperate these mods. But you can download them all and make your very own modpack if you wish.
CCC, XAI and XLRP are all attempts at this, some more successful than others.
As good and as complete as Roguetech is and with all the work that has gone into it. You can download all the mods it uses bar a couple, and then sit down and add weapons and/or configure all the mechs to your liking (a ton of work of course) and have your very own mod pack that is very similar. It would just be a ton of effort.