I agree. And the biggest problem pixel art creates as a practise medium is that it's not very friendly to sketch in. That's why I usually (though not always) do pencil studies to get the composition ok before turning to pixels. A lot of people that work in pixels suffer from composition weaknesses. The habit of drawing thumbnails, selecting the most energetic one, blowing it up and using it as a base of the composition should be picked up by more pixel artists.
Another issue: it's common knowledge that painters are instructed to work 'from general to specific', first in broad strokes and then gradually tightening up and getting down to detail level all over the place. Due to how 'finalized' you can get something to look in pixel art in relatively little time, a lot of people -me included- when they've got the volumes and colors worked out, attack a specific place in the picture until it's done-done, and then move to the next bit... it works, but it's not as easy to see how it's all holding up as you could if you did it the painter-friendly way. It's just that general to specific I've found, when applied to pixel art leads to a uniformly messy piece. Pixel-art tightness seems to occur more naturally when you work a face, a hand FULL-ON until you're DONE so you can look at it as you work other places and see if the detail level matches. If you go from broad to specific, you get to a point where the whole piece is 80% detailed and you subconsciously go "this is good enough" but it's that extra sheen of polish that's missing.
Personally, I battled a lot with how to draw my initial steps in pixel art, and I found I really can't handle and get annoyed by the 'blotted color' painter way to start. I've devised a hybrid clean method of good lineart that gets turned into something that looks like a flat-shaded polygon mesh, and from there it's a matter of smoothing transitions, dithering and detail work. I really can't handle BLOTCH BLOTCH "this is my wip, guys!" I need to know what's going on in the pic and where the elements all are from pretty early on. Probably bad practise if I tried to take it say, to watercolor (which I know how to work, but am very hesitant to).