I've never heard that argument before, except maybe for the NES (mostly because the music was also run at a lower pace). The arguments I heard thrown around back in the day with regards to PAL/NTSC was that PAL had a higher resolution and picture quality. I always prefered 60 Hz over that though because it made some games run that much better (extremely noticable in Tekken 3 for instance). Dreamcast kind of revolutionized this by giving you a choice between 50/60Hz on TVs supporting it though, effectively giving us the superior PAL 60 Hz alternative.
Not really how it works. PAL 60 aka what the dreamcast did was NTSC resolution.
PAL is 576i 50Hz, NTSC is 480i 60Hz. Basically nothing ever runs at 576i 60Hz (and 576p 50z is an ever rarer, progressive signals are almost universally 480p).
PAL games never had higher resolutions, with the lone exception of some Gamecube games which rendered at true 576i (e.g. Metroid Prime 1). At best PAL games stretched the NTSC resolution over the 576 lines to match the aspect ration, and sped up the gameplay and music so the speed drop from 60 to 50 was nullified. At worst (99% of the time) it just letterboxed the signal and ran the game slower, leaving black bars and slower gameplay and music.
There are some small advantages to PAL, particularly the SNES. Music always runs at correct speed on the SNES, because the sound chip is discreet and not tied to the CPU clock. And some PAL SNES games have less slowdown, because effectively the console is the same exact hardware running slower, so it has spare cycles to 'catch up' compared to the NTSC console.
And finally, because PAL software was usually identical, all you need to do is modify the console and the much nicer looking PAL carts and console run correctly anyway. It's an easy mod with almost all old consoles except the NES and N64, Sega consoles in particular usually have a labelled jumper on the board to do the conversion!
EDIT: that said, I run an RGB modded Super Fami Jr for the next picture quality possible, so have ditched PAL completely!
