Every time I have to wash, rinse, sanitize, fill, and cap 60-some odd bottles I wish I were kegging.
Don't get me wrong: There are few joys in the life of a homebrewer that equal the sudden thrill of finding a perfectly good, dark brown, non-screwtop bottle with an easily removable label. In my neck of the woods the local Vienna Lager (Goldstar) comes in these bottles, and it is one of the greatest justifications for the continued existence of that beer (Though truth be told, as far as Vienna lagers go, Goldstar is one of the better examples of the mass-produced breed). I look for bottles everywhere: I have scoped out every recycling bin around my office, and I know which ones have empty beer bottles and on what day. My coworkers have gotten used to seeing a crate of empty bottles in the corner of the office waiting to be taken home, and my friends have learned to put bottles neatly in bags for me. I am the bottle king of my little domain.
But it's a lot of work. Especially if one suffers from a lethal combination of fishing bottles from the trash (often with dried residue and fungus inside) and a compulsion for cleanliness and sanitation that would make a clean-room worker weep with joy. Before any bottle of mine gets filled it had been rinsed out between 6 to 8 times, scrubbed with a dedicated bottle brush, sanitized with contact sanitizer (including the mouth and a few centimeters on the outside), and filled on top of the sanitizer foam. Multiply that by 60 bottles for an average 20L batch, and you'll easily understand why I wasn't that upset when my latest batch of cider turned out sour. - At least it meant I didn't have to bottle it!
So I'd love to keg, but it's not really a realistic option.
For one thing, I don't drink enough. I drink somewhere in the neighborhood of one liter per week. I still have bottles of a Pilsner I brewed in August (and it's still good, which I attribute to the anal-retentive sanitation described above), and practically every other beer too. At that rate, I would be able to use a keg maybe two or three times a year (assuming I just drink from that keg). Hardly worth it.
For another thing, I don't have the cooling. I "only" have the fermentation fridge (I say only in quotations because I'm well aware that many home brewers don't have that, and I count myself blessed to have a wife who doesn't mind sticking a fridge in the livingroom so long as she gets to decorate it). Kegs need to be kept at serving temperatures (not strictly true, of course, but the alternative is an inline cooler, which is another piece of equipment I don't have) where as beer needs to ferment at temperatures much higher. They can't live in the same fridge.
Actually that's not true: I could dedicate my fridge as a keg/lagering fridge and brew ales and lagers based on the ambient temperatures. But I loth to do that. So much of the character of beer hinges on precise temperature control that I would hate to lose that ability just to save some effort.
And kegs have their own problems: They don't transport well (If you want to take some beer over to friends you have to bottle it). They're expensive (compared to the free bottles I get). They don't age well (I have an "archive" of past beers I brewed, so I can taste how they change over time). And they require a lot of extra equipment (CO2, lines, taps, etc).
All of these reasons mean that I will stay with bottles in the foreseeable future. Maybe one day I'll have a large walk-in cooler in the basement and thirty taps lining the walls of the livingroom. But as it is, whenever I have a beer that's ready to leave the fermenter I will be putting it in bottles, and just wishing I were kegging...