It's hydraulically more difficult for your pump to pull water than push it, so it makes more sense to put large strains like a filter on the pressure side. It's also less finicky as your filter accumulates debris for the same reason.
That being said suction side filters are used regularly, just in hot tubs, not pools. The hydraulics are not so demanding in a tub because of the relatively small amount of water, the debris load is low because they're covered 99% of the time, and using suction side filters allows you to connect the cartridge to a simple PVC fitting rather than building/buying a pressurized housing for it.