My brother has two kids (5 and 3), and just from visiting his place I can tell you there's far worse in kids' TV than Barney, believe it or not. For example, "Dudley The Dragon" - makes Barney's dialogue look like frickin' Shakespeare.
The latest annoyance is PC-Kids TV - there's two different shows ("Tiny Tots TV" or something like that, and "Dora the Explorer") where the characters lapse into Spanish from time to time for no reason at all.
It doesn't get any better when they get a little older, either - I spent an evening with a friends' 6 year old a few months ago and can report with bibilcal certainty that "Spongebob Squarepants" is the stupidest thing I've ever seen in my life. Stupider than "Gilligan's Island", stupider than "Manimal" (anyone remember that piece of crap?)...you get the idea.