DLC is all fanservice, the rest of the game isn't like this.
Here's my take on it, from the character depth thing going on a page back or two:
They went more for the entertainment than depth. Yeah, Lethe is a deeper and more "interesting" character than Panne, but I can't recall too many Fire Emblem games where I've found myself just laughing out loud. Yeah, it makes the characters slightly less believable, but to a degree I do actually really say this is 100% worse. FE10 proved that, as far as IS is concerned, Supports are as much just bonus material for the sake of the mechanics as they are anything, and I'll take hilarious one-note supports over FE10's complete barren, "Hey, don't die!" "Okay!" supports.
Personally I'm really, really glad these came over, since now I can get an unlimited supply of Seeds of Trust. For those of you going for supports, there isn't a better way than this.