What was so bad about 'Red Rose Speedway'?

From what I can tell it seems to be a perfectly respectable pop album,
containing a lot of good natured light hearted melodies typical of
McCartney. I've been listening to it good deal lately and I think it's
great, especially things like 'Power Cut' and 'Little Lamb Dragonfly'.

But yet it gets such a bad rap...by everyone. Anything I'm missing out
on here?