If you want the setting to have any cohesion or sense of verisimilitude, yes it does.
/snip
Hint: it's a lot more effort and creativity to run the entire world of a setting than it is to run a single PC. Maybe the player can be "burdened" with a little extra work for a change.
Again, if making a single new character for a campaign causes you this much angst, I really do think that this is indicative of far, far larger issues down the road.
Ok, firstly, could you please not fisk responses? It's extremely difficult to read and I simply don't have the patience for it.
Secondly, I find the whole "I do all the work, so, I get all the authority" argument falls on its face when you don't allow anyone else to have any chance to do any of the work. If you are the sole source of lore for the game, then you cannot then complain when players are not contributing.
See, I haven't agreed to abide by anything. You've pitched the game, I've made an attempt to bring something to the table that I think will be fun for me and for everyone else. You've decided that my ideas just aren't good enough to play in your game, because you've done all the work developing the campaign, without ever actually taking the time to
ask the players if there is something they would like included
before you did all the work and made all the decisions.
Lastly, if adding a plasmoid (as an example) to your campaign totally ruins all cohesion and sense of verisimilitude, then, well, I'm thinking that that's a bit of an over reaction. Oh noes, the player has made a choice that probably in no way actually changes your campaign, has zero effect on anything, and frankly, is probably the least important or interesting part of your campaign (There are no XXXX in this campaign is not the most interesting part of your campaign). How would adding a plasmoid PC to a Dragonlance campaign change anything?
That's the point that's being made - and note, this is a point that has been made and repeated for decades and it never seems to get answered. If you're running, say, Dragonlance, how would the presence of a plasmoid PC change anything? Would the Dragonarmies cease to exist? Would the plot of the game change? Would any of the NPC's, locations, or adventure hooks change in any meaningful way?
So, what work am I negating by having a plasmoid PC in your Dragonlance game?