Is it viable? Yes. Is it optimal? No. Think like a raid leader for a minute or two. In an 8m group, which the majority of runs are, there's a maximum of 2 spots for melee DPS. 1 will go to a Marauder as they have top damage and Bloodthirst. That leaves you competing for 1 slot against all other DPS classes. Snipers, PTs, Marauders, Juggs and Mercs all pull equal or better DPS. Snipers and Mercs are safer due to range. 2 Marauders means 2 Predations and Bloodthirsts, which is a very good thing. Juggs and PTs are both more survivable due to heavy armor. Scale it up to a 16m and it doesn't get much better. BT is only party-wide, so that means 2 marauders to get the buff out to all DPS. and a potential of 2 slots to fill with a Sin DPS. This isn;t to say that Sin DPS is bad or useless, just know that you are fighting an uphill battle when it comes to finding a group for Ops.
You know, I've been part of end game raiding in multiple MMOs for 7 years. I've been a raid leader, an officer, etc. I hate when people talk like this when it comes to putting raids together. You make it sound like all you are in a raiding guild is a number. As if all you are to your guildmates is the class you play.
I've been in many a different raiding guilds. I've joined raids for other raiding guilds who needed to fill spots for a night. Let me remind you I've been doing this over the course of 7 years...I have NEVER ran across this type of attitude before, at least not as black and white as you make it out to be.
In my most recent raiding guild, when deciding who to invite for DPS, we look at the player first of all. We consider the actual damage the player puts out (the PLAYER, not the class...), his awareness and ability to stay alive and deal with fight mechanics, THEN, at the very end of everything, we consider what class he is and what other utilities his class brings.
So, contrary to what many people on the forums will tell you, class is actually the last thing you should look at when raid invites go out. People who tell you you'll never get invited to a raid if you're a certain class are dead wrong. Most raid leaders, from my experience and having been a successful one myself, don't think like that. We aren't robots with no emotions that only consider numbers and not the players themselves...
A bit off topic but there you go.