Aha! Something we agree on! As a kind, I was clumsy and bad at maths, also left-handed. The family doctor told my parents I had 'poor co-ordination'; Sports teachers implied that I might be gay (which was a terrible thing back in the 1960s); maths and science teachers said I was thick (English and History teachers said I was brilliant); my grandmother wouldn't let me use a knife or any other tool because I did it with the 'wrong' hand and my great-grandmother missed no opportunity to remind us all that Judas Iscariot and Cain were both left-handed. Had I been born 20 years later I might (and you will correct me if I am wrong, please) have been diagnosed as dyspraxic myself. I still can't drive a manual car, but need an automatic (not that common over here).
But I like video games. They were the kinds of games I dreamed about as a kid. Many of the books I read, especially the Sword and Sorcery ones, made me long for an interactvie version where I could make the choices for the hero. So now, at 62 and despite my wifes' constant complaints that I'm too old, I hve a PS3, a drawer full of games and an active Steam membership. I play a variety of RTS, action and RPGs. I love Kingdoms of Amalur, Dragon Age, Mass Effect, Civilization, Devil May Cry, God of War and Total War:Warhammer. I always play on Easy, Casual or Story mode and I never play online. I play for fun, not to collect bits of extra kit, special skins or high scores. I get a good deal of gyp from my son about it, especially in stealth-based games like Assassins' Creed, where my greater patience frequently means I outdo him. He can never see why I don't want to challenge myself more.
But for people who just want to play for enjoyment, as well as for those without the reflexes of a hunting cat and the temperament of a hungry wolverine, these modes are essential. I do agree with you also, that more should be done to make these games accessible to the less able. It's not rocket science, after all, and the makers are missing out on a potential market.
BTW, youre braver than I am. After one acutelty dentl encounter in my 20s, I've kept a respectful distance between myself and all members of the equine tribe!