From end game where? PvP or a Nightfall Strike? I don't remember people getting them in any of the end game rolls for regular Strikes prior to last week and so your test basis is just the last few days and with all of this it's random chance. Also if you rushed through those Strikes and avoided a bunch of the enemies or your teammates killed a lot of them and you weren't close enough by them when they did you drastically lowered your chances.