You are not exactly proving me wrong about the lack of incentive to play the perk considering a specialist will be favored over it for any kind of job.I thought myself the Commando is like a default "soldier" class, able to take on most jobs in the absence of others. It makes sense too, being a weapons specialty which is quite popular and versatile, possibly the most versatile of all the weaponry. Also has a decently powerful grenade for extra oomph and help against FP!
Basically if you had 6 commandos you could have them all take the same loadout and have different jobs, and they'd all perform just fine I'd say.
Trash clean: firebug, support, but once decently geared any can do, that's why they are called trash;
Mid/Big game removal: SS is (and I think will be in KF2) faster at killing sirens, husk, bloats and scrakes, so simply better;
FP: teamwork, enough said, demo is only the main damage dealer;
Healing: 6 mandos with heal handguns cannot beat a full-time healing medic, especially with the nades;
Blocking a choke: no one can come close to a zerker or a support at this game.
KF is a game where the players are supposed to take very different roles so they are at top capacity in all fields while their team work allow them to void each and every perk weakness.
It's a coop game.
Can the mando do ok in a pinch ?
Of course.
Is it desirable ?
No.
Sadly the jack-of-all-trade design of the commando does not enter the teamplay equation, it has been its problem for the whole of KF1 and as things are going it's gonna be its problem for the whole of KF2 too.
It lacks uniqueness, and the cheap gimmick of making it unique by being the average perk is not enough, it's too "metagame" to seduce anyone but newbies.