It is more time consuming to take the car to have oil change at either dealer or independent garage. If the oil can be changed without jack up the car using the oil extractor and the filter on top of the engine, then the whole time to do it at home can be done in less than 45 minutes even for a very slow DIYer, I took my time doing oil change for all my cars, it took me less than 30 minutes to change on the E430 but a little longer on S2000 and LS400, and I was not in a hurry. Drive the car to dealer, wait for service writer, wait for oil change then drive back home will be more than 1 hour, can be up to 2-3 hours.
Another advantage of DIY is you can change oil whenever you like, dealer has certain working hour during the week, few hours on Saturday and no service on Sunday.
The only small problem is taking the used oil to recycling center, but it can be done with other chores in the same trip.