Leaking is caused by basic chemistry. An old, usually depleted or at least low charge battery, will experience leaking due to the breakdown of the internal chemistry.
Some people even try to recharge Alkalines which very often ends up in a leaky battery that damages the equipment it's used in.
I always change out the Alkalines in all of the devices I use them in at least once every year if they aren't used during that year (flashlights or radios I keep on "standby" for emergencies). Never had one leak or fail yet.
I typically use Christmas as a the time I do that because it's an easy time to remember, and lot's of new batteries get bought during that time of the year anyway for toys and stuff.
What I do then is to replace all the "standby" batteries in those items, and then use those batteries in the things I use often which is a cheap way to "recycle" batteries until depleted.
Of course, I'm very careful to replace THOSE batteries as soon as they begin to dim.
