If I had a dollar for every time I walked out of a movie in the last two decades and said:
“Well the plot was lame; the characters were awful; but the special effects were awesome!”
I’d still be pissed because I lost $9.00 on a crappy movie instead of $10.00.
A few examples
Star Wars: The Phantom Menace was terrible, but dammit, the special effects were great.
Avatar was trite, but dammit, the special effects were great.
Green Lantern made me sad, but dammit, the special effects were great.
The Clash of the Titans remake defecates on the original, but dammit, the special effects were great.
And don’t even get me started on Indiana Jones & the Kingdom of the Crystal Skull or any of the Transformers movies.
No longer good enough
For a long time I was ok with a crappy plot, and faulty characters so long as the effects were cool. It was a fair trade.
This weekend I came to the realization that it is no longer ok. It’s almost 2012 (2012, that’s another one), and every movie that demands effects has good special effects. It’s just not enough for a movie to just have good special effects.
If a movie can’t back up the special effects with some substance, I can’t be bothered with it anymore.
The Geek Whisperer 
I agree completely. This is why Michael Bay should stop making movies. I think it would serve as a good example for everyone else. Special effects should be used to aid the plot of the story. They shouldn’t be substituted for a good story. And as for that Indiana Jones movie you mentioned, it sounds familiar and I think I even saw it, but I’ve repressed any memory of the actual experience of watching it.