The PBI (‘Poor Bloody Infantry’) are the solid bricks of the army. The infanteers can always be relied on to get the job done. Even when the armoured troops stall, the infantry push on, clearing the way ahead.
Rifle companies are not glamorous. Their job is unpleasant and deadly, but the riflemen can be counted on to do their job, and do it well, not matter how much they complain about their lot.