is there an explanation...

Well I love both and my sister read both genre, I think it depends how you are open about sexuality and how you are confident about your sexuality. I'm bisexual so I'm not awkward to read about girls getting on, but my sister is straight and she read both.

I wonder about that too... but I personally don't think it''s about your sexuality. I love reading yaoi, but yuri just doesn't seem as interesting (to me, of course). I tried reading it but didn't like it. I guess it just depends on the person...

I don't think it has to do about how open you are but more about the depiction of characters.
First I started reading shoujo but I got tired of the "perfect", cute and innocent girl. They are so useless. And usually the manga has some misogynistic propaganda. The girl is only there for the development of the male character who, even though he's not the main in a manga aimed for girls, is the one with more character development. (There are a few exceptions, but still...)
In Yaoi I found that both partners have usually almost equally ground. More similar to the relationships that real people are used to.
But in Yuri I've found that as usual lesbians are only used as sexual fantasies and girls yet again have no character development. (I've read very few yuris so this one I wouldn't take it for granted, maybe this isn't the norm for yuris. I don't know.)

I agree. I started the same way you did, read both yuri and yaoi after that and felt the same perspective regards both genre.

Me too! I read yuri before but only once, it is not as appealing as yaoi

I tried reading yuri before and it just does not do it for me. I'm a straight girl and I have no problems about lesbians and bisexual women but I just prefer reading yaoi stories to yuri ones.

I think so too with regards to yuri stories focusing more on the "what should be" sexual fantasies whereas yaoi stories ( the one's I read) focuses more on character development rather than going straight to the sex. I got tired of shoujo too because I rarely see a female lead that actually has a backbone and doesn't just settle for being dominated by the male lead. I also prefer yaoi just for the fact that the lead can be both cutesy yet tough at the same time.

For me, yuri is not really my type cause they are not too appealing but I do respect them..... I am a reader of shoujo before but quit and shipped to yaoi

1. the story is too "out of this world" scenes (just like the girl confessing to a boy; making of bentou and such)
2. poor character development (especially on the female lead which is mentioned in the comments above)
3. also so boring process (slow attraction --> confession --> dating --> happy ever after or broken hearted or another one coming --> back to step one for broken hearted or resolve problem for another one coming) which is always the scenario of most shoujo ones while yaoi has different flows
4. yaoi sweet scenes are too hot and has different impact... and the scenes commonly done by cute real couples (like patting of head, kissing shockingly, etc.), simply they are on the different level
5. innocent types in shoujo are annoying... honestly
6. as mentioned above, the boys gets the glory in the story, for they are always are being emphasized

Thus, I prefer reading shonen, yaoi and seinen... the plots are surprising catchy

Well for me it has been like comparing plugs and outlets
Yaoi= P(seme)+O(uke)
Straight= P(man)+O(woman)
Yuri=O(woman)+O(woman)
Consensus: There is no spark (electricity) between girls during H scenes.

omg! I'm just like you! I'm a straight girl (I've got a boyfriend that is fine with my "manga-hobbies"(⌒▽⌒)) I tried also reading yuri but I just couldn't enjoy reading them...instead I really like all of yaoi manga (▰˘◡˘▰)

Well guys, I just recently returned to reading shoujo manga.. right now I'm tired of reading yaoi (never liked yuri) mostly the reason is because yaoi has lots of sex (very) steamy scenes that it is now making my head spin.. LOL.. i tried reading shounen-ai but it never got an appeal to me

Keep me posted to all the best manga that you've read regardless of genre and I'll also try to read them