I know what you mean. I've loved iguanas since I was a kid, but I know I don't have the space or time to care for one at this point in my life. Besides, I'm pretty happy with the tegus and the rest of my zoo. 
A lil iguana story... A few years ago, I was at a [insert large chain name here] when a boy was trying to convince his mom to get him an iguana. The sales rep told her it'd get about 2 ft and only ate crickets. (?!?) I am by no means an iguana expert, but I just had to say something.
I pulled her aside and tried to explain that they get pretty big, require a large enclosure, high humidity, etc. She said once it got too big they could just drop it off at a shelter or something. I couldn't believe she actually said that. 
I grabbed the current Reptiles which had a 'top 5 beginner reptiles' article or something, and suggested they do a little research first. The rep got pretty upset that he lost the sale, but the iguana was spared the stress of becoming a rescue... at least from that household.
It's sad that people still choose a $15 iguana over a $50 beardie (or other 'beginner' lizard), without doing any research whatsoever, and just dump 'em when they get large, sick, or unruly, assuming they survive that long. Fortunately, people like jiffypop and other rescuers take in these poor little (and big) guys and give them the care & respect they deserve.
Sorry for the long soapbox rant, I just hate it when animals are mistreated.