Usually anime only get more than one season if they gain large popularity and get good sells or if more than one season was planned from the start. Only having one season doesn't mean the anime is bad/dumbed down, though. As long as the anime doesn't seem rushed.
Just like, imo, fanservice doesn't make an anime bad/dumbed down either unless it's so constant or jarring that it ruins the rest of the show. I've seen quite a few anime in the past 3 years that have no or very little fanservice, although them being over 13 episodes is iffy.
Anyway, Space Brothers, Love Live, the Berserk movies, S-Cry-Ed Alteration movies (its a remake, basically. S-cry-ed is really good imo, though.), Jormungand, Jojo's Bizarre Adventure, Magi, Hoozuki no Reitetsu, Mushishi (counting it since it got a new season in the past year or so), Tonari no Seki-kun, Barakamon, and Hanayamata are things that I can suggest that I have seen, are good, and have pretty much no fanservice and have aired in the last three years. (well the berserk movies are iffy but ONE of them was released in the last three years.) I've also heard a lot of good things about ping pong the animation and I'm pretty sure that has no fanservice, although I have yet to watch it.
I honestly don't even watch that much compared to a lot of my friends. I'm no casual, but I don't have a huge rep of hundreds and hundreds of shows I've watched either. So theres probably a lot more good anime in the past few years with very little fanservice that I've missed.
tl;dr you're probably just not watching enough anime or the particular genres you watch (slice of life, for example) are fanservice heavy. My suggestion is; don't get offended/bothered by fanservice easily and don't judge an anime by how long it is.
My answer to the original question is no. I don't think they're worse. Sure, really good anime can be few and far between, but they were few and far between in the past as well. Really, it probably just seems like anime are worse now to you because, out of the anime that aired in the past you've probably only watched the ones that are rated really high or considered generally good anime. With the new years, assuming you've been watching seasons as they air, OF COURSE you're gonna run into a lot of crap because the good hasn't really been separated from the bad. The old bad anime (unless they're so bad they're laughable) have just faded out, so you feel like theres less.
Anyway, this is all my opinion.
Also, just to clarify, my suggestions don't all have over 13 episodes. Because I think its dumb if you count the length of an anime into considering it good or not.