Newbie here. I've owned mine for 2 months now. I agree. I bought the case with light, and I found it the same. I think those that came from the 300 series or 500 series (smaller), or previously used a cover with light may have gotten use to it. I tried for about 2 weeks, but realized it was just a lot more comfortable to hold naked. I really got lost in the read. Personally I didn't have a problem holding it without a case. It all depends on the user, I suppose. Some iPhone users (I own a blackberry), prefer an otterbox, and some a slip case, and some naked.
My logic was I'm not checking my ereader constantly, like my phone is. It's either in my pocket while on the go, and when I'm reading I'm sitting down by myself, or on the train. Meaning, while on the go, a case would be nice option, but when I'm reading I want it light and comfortable. I did find it easier to hold with the cover folded back, but it got heavy after a while. If I carried a brief case with me everywhere I went, okay,,, but I don't. Personal preference. I like my reader thin and light to be portable and easy to hold. I do have to be more careful with it. But like my blackberry I've never dropped it, and have read daily on the train and in my home. I've never dropped my reader.
I suppose even if you did drop your reader in the cover, it would just flap around and still might land open with the reader facing down on concrete, in which case you still may be SOL. In my opinion, go thin and light with a slip. Just my opinion though. It all depends on how much of a clutz you are. I knew a guy that dropped his new wallet in the toilet, and new Zune on the first day on the concrete and cracked his screen- $40 bucks to replace the glass. I'm not like that though. And I hope most people aren't!