i think it's cool now and then. i liked "hard knock life" and "down down baby", but A LOT of rap nowadays is HIGHLY derivitive of not only old nursery rhymes and stuff like that, but of ITSELF! they bank on recognition, nostalgia, and things that have worked in the past. how many times are rappers gonna say "gimme the microphone first, so i can bust like a bubble." or steal a Biggy rhyme and then call it an homage. I kinda got off the point, lol but kinda dig the kiddy song sampling if it's done creatively, but trite and overused samples of cheesy stuff is silly.
yea, you're right, they always use eachothers stuff. i hate rap. and why the heck do they curse so much? they'll make a whole "song" out of two words. even though rock songs curse too, DEF. not nearly as much. ugh, i HATE rap. (except for the few songs i like, haha)
cursing in rap nowadays is more to fill syllables than to express seriousness or a give a strong vibe. it's so dumb. SOME rappers can write really smart stuff and stay light on the cursing, but some dumb rappers use the cursing as a crutch.