There are other reasons to take a laptop home. For instance, at my workplace, the night before snow is predicted, nearly every single person will want to take their laptop home so that they can work from home the next day if it snows. If your laptop pool is smaller than the number of employees, there won't be enough laptops to go around.
Every single person will want to, but how many actually need to?
Clearly it all depends what kind of business you're in, and how often adverse weather like that happens and how long it lasts (I'm speaking from a UK perspective where every few years there's two flakes of snow which cause carnage but have usually melted within a few days...), but if the result of a disrupted commute is that the HR people can't get to their email for a few days, the world isn't going to stop (see also: bus factor).
There's always remote access too - Citrix/SSH/RDP/VNC into your machine from afar, avoids having to install crap on your personal machine and the company still has control of their IP.
I just can't imagine a software developer not owning a computer. Its a basic tool of your craft. I always have my own tools. An employer might prefer that I use theirs at the work place, but I dont depend on it for my livelihood.
