I tend to agree, the Alumni group posts starting salaries here: http://web.mit.edu/facts/alum.html but I can't find their 5 year and 10 year numbers. I expect that the median for 10 years would be north of $200,000.
The vast majority of fields are simply not lucrative enough for the median salary to be anywhere near $200,000/yr. A chemical engineer is typically unable to create anywhere near as much value as a software developer at a leading company and is compensated accordingly.
Yeah, per that site, the average starting salary for all MIT undergraduates is $75K/year. That's really damn good. Filter it down to just the software engineers and it'll be a good deal higher. And there's so much upside left too.