Well I haven't used a genuine filter for years & had no problems. I tend to choose recognised aftermarket brands though........
And although I uses garages for most jobs, I always like to change the oil myself, just to make sure. Call me paranoid...!
I would hazard a guess, that using the dirt cheap aftermarket filters won't be such an issue on much older cars, but I believe folks should be careful what they use these days with modern cars whereby the engine manufacture tolerances are far more finite these days than perhaps they were 20, 30 years ago etc. Lots of cars these days seem also to need the requirement to have the oil change reset done and clearly this is the case with our own TA for instance.
Having spent almost 10k on a new car, I'm not about to start substituting the OEM filter for any other branded filter, certainly not under my ownership anyway.