Tiny habits have great power.
I read yesterday in my running magazine that adding three Oreos daily to your usual diet will gain you 17 pounds in a year. (So that’s where they came from, hmm …)
And learning just six kanji per day will get you through the entire jōyō kanji in a year. This “insurmountable task” can be done in a single year with hardly a trace of effort.
Lan'dorien's Mysterious Journey 
Yeah I learned that the hard way (with the Kanji) after failing to finish the Heisig book 3 times before, I went too fast. But I started again in Nov. last year doing 10 a day and no more than 50 expired cards and I’m at 1780 now. I could never quite get to 1500 before that. And that’s crazy about the Oreo thing, you know those plastic packets they come in with you buy a box? I used to eat an entire one (probably was 18 or so cookies) at once. I didn’t really gain weight cause I was younger but I certainly don’t do that now.
I’ve made a couple false starts on the kanji too. My previous best was over 500. RTK has been a minor revelation for me.
I love the kanji so I have a pretty high tolerance for a fast pace. I’ve done up to 80 in a day, although that takes me most of the evening 🙂 But anyone can learn them – unless they quit. That’s the only certain way to fail. Taking the long view, having patience, doing a bit every day, and success is inevitable.
(and now I feel like I’m preaching to my guitarist self. Maybe I blow the dust off today and get going again …)
Most of the time the people who tell me Japanese is difficult are the Japanese themselves. Maybe they feel insecure about their own failures in learning English that they have to put that across to everyone else.
I say put forth the time and effort into it, and if you fail then it’s your own fault, not anyone else’s.
You’re right though, 6/day is more manageable than try to do all at once.