Well, possibly. If you're going for a reeeally long time somewhere, it may just make sense to rent a car instead of paying to have your car sit in an empty airport parking lot.
There's a lot of advantages to self-parking, especially if you can't convince anyone to drop you off or come get you at the airport. (Then, my friend, I believe we don't really have a choice.) Though there's SuperShuttle or the occasional taxi, if that's too expensive, renting a car may be a good way to save on airport parking.
Now, clearly, this comes down to a few factors. Namely, how long are you going for? And how much is the daily rate? If you're only going for three days and it only costs $5 a day to store your car, by all means, go ahead and park your car in storage. But if you're going for a few weeks or whatnot, you can take advantage of one-way car rentals to save several bucks.
Rental car companies (or, well, the good ones anyway) will often pick you up and drop you off at home for free if you live within a certain distance. Top this off with the fact that many car rental companies have a presence at airports, and, all of a sudden, this is a viable option, if not a slightly indirect way of getting to the airport.
Imagine for a second that you're going away for quite a bit of time; let's say for a period of 10 days, a rate of $10 per day is going to run up your final tab pretty quick. In the end, it's going to end up costing you $100.
If you can reserve a car near your house and drop it off at an airport location for relatively cheap (let's say under $30 a day; we do post deals on Twitter every now and then) and manage to do the opposite when you come back, you'll end up ahead. You'll still get to your house - albeit for $60 in total, a good $40 less than what you would have ended up paying.
People rent and store cars at airports all the time to save on taxi fees. This is just pretty much the same principle.
