I'll admit, some of the problem is that knowledge skills were always a lot more subjective then active skills, since you could litterally just make up ones of your own on the spot. Even with the same level of overall knowledge people will know things differently.
Take three chummers who got a degree in English from Ares University. All have the mechanical level of 6 in the skill, with LOG of 5 and INT of 4 for arguments sake. All three could still play this up as being different from each other via roleplaying, with one focusing on things like sentence strucher and the nuts-an-bolts of who language works, while another focused his studies on story composition and writing. Both with the same dice pool but they know things about English differently from each other.
While it may be a problem when someone wants to recall facts about their knowledge with a skill roll, it also lends itself to players being creative with their knowledge skills once more, rather then focusing their few points into only "street useful" skills and ignoring any sort of character building interest things. Having a character with a knowledge of bonzi tree shaping is a fun and could be rewarded in game somehow without needed to roll separately for, or a character doesn't feel bad 'wasting' knowledge skills taking 20th century TTRPGs for his mage named Hoyle (actual reference, cause I'm a nerd).
Language skills though I'd probably still want to see a skill level on as I feel that's more mechanically important, but then again I can't think of more then one hand worth of examples of when that skill level distinction actually mattered in all my years of Shadowrun.