Considering sniper cheese was and still is the meta and considering how vulnerable brens are to dying after one faust and some small arms fire, it actually may not be as surprising as it first seems. Bren is the obvious counter to snipers, it's just hopeless at it. After getting buttraped by snipers in a few games people probably stopped building second inf sections in favor of trying to preemptively counter the snipers. No extra inf sections and investing in engineers heavily is also another strat since the bleed is less costly.
No way, everybody at least makes 1 infantry section. You don't make over 6 bren carriers in a game (this would assume only 1 extra infantry section is built in every game) to counter the enemy snipers. There is no possible way that is accurate.