Yup we all get testy with each other from time to time... From the ground, it probably has more to do with frustration with stupid pilot tricks that we see day in and day out with a GREAT lack of profesionalism from the cockpit of late. Not following what is on the chart and blindly following the FMS even though it was programed wrong and then getting testy when the controller in a loud voice tells you to turn immediately you are off course, and then issue traffic. The controller is probably using a crowbar to pry the seat out of his/her butt from watching someone turn into another aircraft. No call signs, not listening for weather being issued to EVERYONE who is departing and then five minutes after being given ride reports, the pilot states, it's getting bumpy any rides ahead <sigh>... It is stuff like this that just drives us NUTS!!! You can only take so much of it before you just shake your head and sound somewhat annoyed by it.
Then as stated, how about the folks who THINK that they have the flick of what is going on traffic wise and keep trying to help you run the sector. Then add in the added frustration of short staffing, screwed up watch schedules and such, and you have folks who are just not in their happy place anymore... You will hear the frustration... Sorry about that, but it is human for the most part...