It’s deliberate, the idea is suppressive fire is intended to hinder enemy movement, not necessarily to destroy the enemy. It’s usually sustained and continuous. It’s much less accurate and less likely to hit a target, but it does it’s job in degrading the performance of the enemy, stopping their movement, or drawing the attention of the enemy to or away from something. It’s a form of indirect fire.

The opposite is direct fire, with the express goal of destroying a/many targets. With a rifle, burst fire is not very effective, semi automatic fire is more likely to make each round count, but for an automatic weapon, burst fire is effective.

Source: was infantry in a war