What's the big deal ?
If you don't want to put in the time don't fill it out.
If you do, fill it out with your true beliefs. Don't sugar coat it or use it to vent--just an honest assessment of what's going on.
If they hired shrinks to do this, they would better have spent their money in coherent negotiations. Or reading the internet or just asking the girls downtown. It's no secret that things aren't going well in terms of worker satisfaction and this is becoming unhappier by the minute.
Up to you but if someone comes back later and says "our survey is rosy" and you didn't fill it out, just like an election, you don't have much to squawk about.