True. Every car has it's weak spots (cluster pods on the TT for example!) and in all honesty, that's down to the buyer to do their homework before purchase and barter accordingly. For example, I was put off buying an E39 M5 because of their common problems. I could easily have bought one blind and had a riot with it, but a few K later it could have cost me £1000s!
And with GTIs, some googling will reveal - potentially high oil consumption, blocked injectors, cam chain tensioners, HPFP followers, subframe creaking, split DVs, broken PCVs, DSG mechatronic issues etc etc. Not all cars suffer with this stuff, but it's good to do your homework to find the right car. The best cars will have paperwork demonstrating these things have been addressed and are worth paying the extra for imo.