I see your point there. Developers would have to be very careful so that the game aesthetics resemble Contra, and that the music sounds like Contra. A Contra game with epic orchestral Hollywood type of music just won't work for me.
I believe that Contra is in top form right now with relatively recent releases like Contra 4, Contra: Rebirth or Contra: Hard Corps Uprising. I'd like it to stay that way. But if they make a new 3D Contra game, at least I hope it looks and sounds like a Contra game, and not like something else (which I like separately, because I love Modern Warfare 2 and 3 looks and soundtracks... just not for Contra). But I understand what you say and I really see the possibility now that I gave that idea some thought.
As for FPS, I never liked them because I never played them and I associated them with (as Lely said) stupid people. But after playing both said games (MW2 and 3) my mind changed. Previously, the only shooter I can recall playing was Resident Evil 4, and that was a 3rd person shooter, so it counts only a little. Oh, and FF7 Dirge of Cerberus too (Shelke is so cute! ♥).
And the final gigantic thing that happened to me was playing the Bioshock saga. I loved all 3 games and they became all-time favourites for me, so I guess I can say that Bioshock changed my mind in that way.
And the last thing was playing The Last Of Us (3rd person shooter). It's one of the games I've enjoyed the most (not without flaws, but it's something unique and majestic).
And now, here I am, soon to be playing Dishonored, Metro: The Last Light, and waiting like crazy for 1886: The Order, all of them shooters. So, I am a changed player right now.
I used to say no to modern games, no to westerns, no to shooters, but they changed my point of view with masterworks.
So... let them make Contra, but please keep the music and the looks of Contra.