Honestly I don't care what people do. I have several co-workers who have developed attendance patterns (off mondays/fridays) and some of my other co-workers are quite vocal in their displeasure about it. I always tell them (the angry):
1. that it's none of my business
2. that as adults it's their job to keep or lose,
3. they know why they come to work and if they choose to risk it, so be it.
On the other hand several of the angry employees are the type that have no lives, take no vacation are single, live alone, with parents etc and I feel that alot of the anger they express is due to their jealousy that these folks (the absentees) have lives, go on trips have children and spouses...
I go to work and I take my days off (vacations). I usually end the year with days owed because I rarely get sick.
As far as being burdened with an extra workload, I do what's put in front of me. When I'm on vacation somebody has to pick up my slack. I do my job, short staffed or not. I understand that chronic, abusive absenteeism should not be tolerated however if you don't like the company's attendance policy you should seek employment elsewhere.