Let's say some hot-headed young strong man has done six months of boxercise or kickboxing and hasn't learnt that there is always someone better than himself and his coach hasn't taught him not to pick fights in the street. He's had a couple of drinks and it's night time. He finds some excuse to start throwing punches at your head. He doesn't rush in allowing you to use tai-sabaki to evade his rush and he isn't stupid enough to grab your arm if you were to offer it (which of course you don't). However, he has enough skill to do a barrage of reasonably effective punches and maybe a kick as well without being substantially off balance and being skillful enough to recover those punches should they not make contact. Aikido doesn't adequately train for that scenario and this is partly because this sort of scenario (a semi-skilled kickboxer or boxer) was not common in feudal Japan, so suitable responses were not developed. However, this scenario is now common and so aikido needs to adapt/evolve and adequately address this type of scenario.