Steam makes it pretty clear that your queue and recommendations are absolutely NOT based upon your preferences at all. They even tell you what it is based on -

Steam makes it pretty clear that your queue and recommendations are absolutely NOT based upon your preferences at all. They even tell you what it is based on - a game is popular, or it's new. Big publishers might be displeased with a solution that used by-now-standard recommendation tech. It certainly wouldn't recommend any AAA titles to me as even though I have 1000+ games in my library (which I never play... I might have a problem) I haven't purchased a $60 on-release-day title for well over a decade. How horrified would Ubisoft and Activision be if they knew a lot of people never even saw mention of their latest title? And first and foremost, Steam appears to be built for them.