From what I've seen during my 35 years of gaming, Charisma seems to be "the" dump stat of the various D&D editions. I never fully understood why, as Wisdom and Intelligence can serve the same purpose for most non spell casters without giving you a negative reaction adjustment. Or maybe I understand why, but don't agree with the "why."
Wait, your DM doesn't take Charisma into account for reaction rolls? Heck, he doesn't even bother with reaction rolls? Yep, that's how we were as teens - Charisma adjustments got handwaved and therefore Charisma become the dump stat.
High intelligence gives extra languages, high Wisdom gives a bonus for certain spell saves (at least in AD&D) but if you are ignoring Charisma adjustments to reaction, loyalty and even more importantly - maximum number of followers, you're playing it wrong (IMHO - your opinion may differ. No opinions were harmed in the writing of this post. Lack of sleep due to overtime and puppy power may have influenced this post. Don't post and drive.)
One of my favorite characters had a 5 intelligence and 7 wisdom with decent combat stats and a 13 for charisma. Of course, I named him Gru and he had a fondness for cheese dip...