Just to add to all the good reasons posted, an all-grain batch can take 6+ hours, but it doesn't have to.
If you plan ahead you can reduce the length of your brew day by getting your grain bill weighed out and ground the night before and your water ready (takes about 45-60 minutes of prep depending on how many beers you drink during prep). You can chop off 30-45 minutes heating water especially if you get yourself a bucket heater (or in your case maybe mroe than one) and timer. Your water can be ready to go when you roll out of bed and you can mash in immediately. 60 Minute Mash, 30-45 minutes to batch sparge and get the to a boil, 60 minute boil and 15-20 minute cool down with a quality chiller. You can knock out an all grain batch in 3.5 to 4 hours for a 6 gallon batch with clean up, wort oxygenated and pitched once you have your process down.
With the large batches you brew, there are things that may take you longer, but pretty much only adding a minimal amount of time to your process at a huge savings! I brewed a 6 gallon batch of 1.045 American Lager last year for $8.30!
How long does it take you to heat up all that water for a 25 gallon brew day?
Even if you don't decide to go all-grain there are still things you can do to shave time from your brew day.