Okay, in theory I get your points, but in practice I've never seen that happen. I've played several games in the past that had VoIP in game and none of them had those issues.
Holdfast is a game that has large battles with up to 200 players I think? VoIP gets messy with that many players, true, but most people embrace it and see it as a positive side to the game.
In my eyes voice comms are a great addition when it has the following caveats:
[list type=decimal]
[*]Voice is on by default, but uses push to talk, and can be disabled entirely by players and by servers. If a server has it disabled, no voice whatsoever on the server.
[*]Voice is proximity based, so you can't hear people shout from across the map.
[/list]
I think it's still a fair point that people will take the game less seriously, especially on larger servers. However, I also think that's already the case in Warband. If you take a look at the largest public servers in NW and Native, you'll see that it's filled to the brim with yelling children and nazism already. Those people don't need need voice comms, unfortunately. So while voice comms would probably make that even more prevalent, I also think that it would reinforce more positive servers and communities.
Additionally:
[SOTR] Roy said:
2. Comms for clans/guilds need to be heavily disciplined, at the very least able to mute or ban somebody. This is not possible in game, unless you were an admin on a server.
Yeah, voice comms for clans or guilds will probably take place out of game regardless. That tends to happen in games with voice too, because like you said there's usually a lot less you can do with in game chat as a group, so you need a third party app to really have full control.