This is a classic problem for many games... but not all games.
No Social Resolution System
So, you're playing D&D. It gives you rules for fighting, running around, light sources, a lot of things. When it comes to player characters solving arguments amongst themselves... you have nothing.
So what happens is that players become used to "Let's do X", "Let's do Y!" arguments taking forever, solving nothing. What solves something? Action. As you've noticed, this always favors impulsive direct action over NOT doing something.
Now, there are games which don't have this problem. Many games have social resolution as an option which allows players to negotiate with each other and group choices become more viable.
- Burning Wheel has Duel of Wits - a social conflict system designed specifically because the designer got sick of people taking forever arguing in game.
- Poison'd has "bargain" mechanics - there's mechanical bonuses you get by striking deals and a way of making people suffer for breaking them
- Sorcerer makes social deals a single roll and breaking them gives you a dice penalty
- Primetime Adventures treats all conflicts the same - including social ones
...and there's plenty more out there.
Once you have a viable social resolution system: 1) arguments end quicker because there's a system to force it to a conclusion, 2) players have more incentive to actually negotiate rather than risk getting a decision forced down their throat, 3) socially inclined characters tend to get a little more leadership, which is generally true in life.
Hacking it for your game
D&D's historical weakness is that when it attempts to give social skills, the results of a roll are often ill defined - which has led to people either declaring them completely useless, or ridiculous - "I convince the king to give me his kingdom! I hit a DC35!".
What you want to do is set up stakes before any roll. Make sure the stakes are reasonable for the characters and that the players are ok with it - if you lose the roll, your character is going to keep the agreement UNLESS something significantly changes the situation.
Players can make their arguments on each side, then roll the dice. If it's something which affects the whole group, players can vote to a side - give each vote an extra D20 to that side and take the highest.
Side A has 3 votes - roll 3D20, take the highest and add the appropriate skill.
Side B has 2 votes - roll 2D20, take the highest and add the appropriate skill.
Appropriate skill isn't just social - "Knowledge: Animals" might make a lot of sense if it's directly related - "If we go back to town now, all we'll do is give it a scent trail to follow to the villagers." etc.
Contrary Gamers
There is a subset of gamers who do not want to play as a party, but they get fun from wreaking the party's plans and causing chaos. There is no rules or techniques to fix the situation. You can have a discussion person to person, but that's about it. They can either agree to play the same game everyone else is trying to play, or find someone else who is running that game.
"We're playing a game about a band of heroes, working together, to
do this thing. That's the kind of campaign everyone else is here for.
If you're not interested, thanks for your time, and I'll let you know
if we decide to do a non-party kind of game in the future."