Improvised plunger-type fuzes depend on the bomb(let) falling straight down. This ensures that occurs, but takes up very little packing space compared to a more conventional empennage. A straight up-and-down attitude also tends to increase the efficiency of fragmentation bomb(let)s.
Secondarily, slowing the weapon can be useful for low flying platforms. Retarded bombs use spring-loaded airbrakes, inflatable ballutes, and/or parachutes to slow the weapon enough to allow the bomber to escape damage.
Example: parafrag bombs in WW2, extensively used against soft targets. The USAAF found them three times more effective than fin stabilized fragmentation bombs of the same size.
I hear you, but I also look at how bombs are typically being used in Ukraine; they're small enough not to present any risk to the drone that's dropping them vertically usually on unfortunate individual soldiers).
Secondarily, slowing the weapon can be useful for low flying platforms. Retarded bombs use spring-loaded airbrakes, inflatable ballutes, and/or parachutes to slow the weapon enough to allow the bomber to escape damage.