Are Debut Books Better?

It has been a disappointing month for me in the reading department. There are several books I have been anticipating, all new books from authors I love. Of the four books I was eagerly waiting for, I was let down by three of them.

On one of them, I didn't get past page 50 because it was all backstory and informationg-dumping and I didn't care enough to keep going. Another kept my interest through the whole book, but I was constantly thinking "Did an editor even look at this?" because I felt the writing was a bit... well, sloppy. Another felt like a retread of the last book.

I would expect this from some of those author machines who churn out 2 or 3 books a year, but it surprises me in literary and commercial fiction.

If I had to go through the last twenty books I read and rank them for how I liked them, debut books came out on top by a long shot. It had me wondering -- is this because in this tough publishing climate, debut novels have to be better to get published? Once an author has a track record, are authors, agents, and editors taking less time to make sure the books are better than perfect?

I'd love to hear some opinions on this because it has me wondering if it is just me reading too critically these days.