Not really. While I get what you're saying, and I agree that much of roleplaying involves making decisions from your character's perspective, there is also a division between player and character, and there are some decisions that the player makes for the game that aren't from the character's perspective. Most of them would be at character creation...such as what stat to put into Constitution.
As the saying goes, the game is everything that happens
after you meet at the tavern. Character creation isn't part
of the game; it's the homework you do
prior to playing the game.
To use an analogy, playing a game is like watching a movie, and making your character is like deciding
which movie you want to watch. Regardless of your external choices, they don't have any effect on the quality or integrity of what happens
within the story. Or to put that more generally, you can't fault the premise - you can only fault how things are handled from there.
It's not my place, as a player, to tell you that your character needs at least a 12 in Constitution and an AC of at least 15. It's
my place to play my own character, and it's my
character's place to tell
your character when they're doing something that needlessly endangers the lives of everyone involved.
What makes the scimitar weaker than a longsword? In what way is it weaker? And why would a character place importance on that factor more so than on any other factor that may play into the decision?
Imagine
every possible metric for comparing the two - speed, weight, ease-of-use, stopping power, whatever. The longsword is equivalent-to or better-than the scimitar along
every single metric, with the sole exception that the scimitar is easier to use with such fighting styles as the character has expressed no interest in using. It doesn't matter which factor they are using to make their decision, because they all come out the same way.
Although, stopping power really is the most important metric, when evaluating a weapon; it should
at least count as a tie-breaker, if the primary deciding point is inconclusive, like with weight or ease-of-use.