Explanation: New Romaboos often like the Praetorian Guard, because, conceptually, they sound cool! Who doesn't like the flashy, fashionable elites of a feared military? And historical games, especially, often feed this perception, as 'Praetorian' is a relatively well-known term, and most games like to have 'elite' units for gameplay purposes.
In reality, the Praetorians were not really a warrior-elite as we'd understand them. While they were the Emperor's bodyguard, they were often derided as parade-ground troops at the best of times; and furthermore, saw more action as a brutally repressive secret police than as a proper military unit. Recruits sometimes transferred in from the Legions, but usually, they were middle-class native Italians without experience joining the Praetorian Guard directly, enjoying a higher pay rate and lower service time in exchange for the cushiest damn posting in the Empire.
Not only that, but the Praetorians were notoriously disloyal, as both secret police and institutionalized bodyguards before the modern era tend to be; as well as having the usual soldierly vices of corruption, brutality, and arrogance, which made them resented by the common people.
And to top it all off, in the few times they did see open combat, they almost always performed fucking terribly. C'mon guys. Is it too much to ask that you have SOME redeeming feature?