The thing is, there are many more lowborn courtiers in ck2 than there are landed families, at least at game start. If you play outside west Europe, you'll notice most characters on the map have no family (except the heirs who were added back in 2.0 or so). For every count/duke/king/emperor, Paradox spawns 4 lowborn men + 1 man with a random dynasty in addition to 1-4 maidens (depending on the character's religion). That means at game start, a count, duke, or even king or emperor with no family will have as many as ten random people at court (it totals nearly 9,000 of these lowborn characters at all times the game is running). So a large ratio like 10 to 1 certainly affects performance -- paradox effectively conceded as much when in the 2.4 patch they reduced events for unlanded courtiers from once per day to once every 20 days: this was a major element of their 2.4 optimization efforts.
But besides performance, a 10 to 1 ratio of anonymous, history-less characters vs real characters in a game about characters, relationships, and history is just plain weird. It is jarring to the mood of the game, distracts, and disrupts suspension of disbelief. Above I asked Zohtun how long s/he plays each save. Anyone who plays this game more than a couple centuries knows CK2 doesn't really get good until dynasties have grown large and resultant dynastic politics become as complex as the families are large. Paradox coders designed the game as a constant race to the prize: each character is programmed to constantly suss out ways to improve their rank and prestige. This is why you'll find the wife of the third son of the baron of nowhere murdering her newborn niece: because that wife is programmed to improve her station by getting her husband and sons as close to the baron title as possible. When such relationships and the proximity to titles that come with them are absent however, the trigger for the game's dynastic intrigue engine is absent: in other words, no family equals no intrigue. So these random characters are sitting around bulging the game at as much as 10 to 1 and yet they can't even participate except marginally on the off chance a seduction focus noble decides to get them pregnant.
So yes there is a performance concern here on the one hand, but on the other there's the issue that these characters just have no place in the game. They serve absolutely no purpose and go further to significantly distract and disrupt the game's purpose and it's main features.
Lowborn courtiers are just a poorly-thought through holdover from CK1. Whoever originally conceived CK thought to themselves, 'there should courts and councils for palace intrigue.' But since all the intrigue is tied to dynasties and landed titles, these courtiers are just deadwood. The designer also included them as a crutch at game start so players wouldn't have to scrounge for a wife and councillors. But as several writers have said here, there is no difficulty finding wives or councillors in this game. And more, the game actually penalizes the player for marrying these lowborn characters. So they can't even effectively fulfill the one role they are designed to.
Finally, it's particularly galling that paradox includes these deadwood characters at exponential levels while disallowing the playability of barons and inland mayors (not to mention disabling their title histories) ostensibly for performance reasons. So again, these lowborn courtiers are just poorly conceived and have been left in the game only due to habit. They should be removed.
