It's offensive. The skit is pretty much an extended Polack joke, only about another group, and in equally bad taste. But then, SNL hasn't been funny for a long time.
And by the way, my last two experiences at the DMV, one of which was on the busiest day of the month, were very positive, and the employees there went out of their way to help me with two very unusual problems.
The fact is that public employment generally has gotten a lot better and today it is easier to get rid of people who don't pull their weight. As to Feds, it's important to recognize that before Civil Service we had the spoils system, which was so bad that it even got one President assassinated. Today I think there are more hiring abuses at the top, where political appointees are allowed to "burrow in" despite having no real expertise in their area of employment. I'd like to see SNL do a skit about that. Unfortunately, that could only happen if they knew what they were talking about.