This is exactly it. The few experiments there have been had to handicap the PC players or give auto-aim-like advantages to console players.
I used to play Counter-Strike professionally and especially at that level, but by no means limited to it... you simply can't match the precision and control of a mouse (which can move freely at whatever speed and acceleration/deceleration that your hand can move) with the analog stick of a controller, which can merely be pushed in a direction until your crosshair eventually gets to where you want it, at which point you can re-center it (assuming you didn't under- or over-shoot, which again is much easier to correct for with a mouse).
But I don't mind the idea of cross-platform shooters that excludes the PC, or forces the use of a gamepad on the PC (though I honestly wouldn't waste my time on that). Shooters are really best played on a PC with a mouse and keyboard anyways, so I suppose I wouldn't mind a completely cross-platform shooter as long as a) the gamers who insist on playing on consoles just accept the inherent disadvantage, and b) random matchups on public servers attempt to somewhat balance the teams in terms of the ratio of players using each control scheme... being able to play with the superior M+K combo wouldn't mean a whole lot if you could just end up getting stuck on a team with all the disadvantaged players.
