Yes, because that is the kind of character I want to play.When a Bard boosts CHA s/he boosts her core performance (ie casting).
Right. So you dump STR and CON.
My character with an 8 strength and 15 int and 14 charisma is capable in melee. Better at ranged, but still good enough in melee.I don't know if @Minigiant or any other poster agrees, but to mind the quintessential battle captain - say, Faramir - is capable in melee. In D&D that means STR and CON can't easily be dumped while retaining that capability. (I guess some battle captains might be high-DEX musketeer types, but clearly that's not Faramir or Eomer or Richard the Lionheart or Jeanne D'Arc or a range of other exemplars a player might draw inspiration from.)
Constitution is overated IMO and does not give you many more hps anyway.
Richard was a crussader and is the archetype for a Paladin which uses charisma as a core ability.
They can support combat with INT and CHA already. Any character can do this, regardless of class.The basic framework of the D&D ability scores probably isn't going to be changed at this point. But it's trivial to change other parts of the game to better fit with them. Allowing a battle captain to use INT or CHA to support combat in some fashion - yet to be fully specified, but obviously some options are being canvassed in this thread - reduces the pressure to ignore those stats in order to ensure viability at the character's key role.
Unless your role is a spell caster, the characters "key role" is for the most part determined by the player, not by the class. If you want to play Faramir then invest in Charisma.
The logic of using STR for Intimidation is that - in the genre, and perhaps in real life too - Fafhrd is more intimidating than The Grey Mouser. And the way to achieve this in D&D, given the stat framework as it currently stands, is to allow the use of STR for Intimidation.
I think that is absolutely not true in real life and makes little sense in d&d world when you can have a 3 foot tall halfling woman deal 100 damage in melee.
I have seen plenty of "dumb jocks" in real life that are muscle bound and not intimidating at all and then other people like gang members, thugs and anyone with a gun that are small and very intimidating. I think being strong may play into it, but it is your ability to use that and leverage that during interaction and that is charisma. A muscle-bound buffon will not intimidate many people, while the mild mannered cold blooded killer will.
If you want strength(intimidation) the rules are there but in my games it is always charisma and the specific threat you use sets the DC. My fighter above with an 8 strength would have a high DC if she threatened to bash your skull in, but would probably have a lower DC if she cast minor illusion and showed the guy a picture of his house burning down with his wife in it. Either way she would use her 14 charisma.
Real in game example - she is a 5 foot tall teifling and we were interogating a prisoner. I used minor illusion make my face show a devilish visage and put glowing circles in front of my eyes. I told him I was putting a curse on him and if he lied he would be dragged to hell. Another character helped by casting prestigitation and making it hotter around him. I rolled an intimidation against a DC 10 with advantage. If I had threatened physical harm if he lied to us it would have been a much harder check. If the Barbarian (whos is strong) had threatened physical harm it would have been a lower DC than me threatening bodily harm, but probably not as low as I got it without some creativity on his part and then if he did not have the charisma he would not get the bonus.
Spellcasting and race aside I would think assassins would present the most fearsome demeanors as their art is killing people.In the fiction, you could suppose that barbarians and fighters, being the toughest warriors, present the most fearsom demeanours.