Thread respecting it here:
http://www.mameworld.info/ubbthreads/showthreaded.php?Cat=&Number=121877&page=0&view=expanded&sb=5&o=&fpart=1&vc=1

Some points (posts) include...

From AWJ:
"The way I've heard it, some spambot discovered the boards and shat all over them (I know this part is accurate--I saw the front page of the Fun/Fluff board full of herbal viagra ads a few hours before the end) and when Gridle tried to clean it up, the whole creaking thing collapsed".

From AaronGiles:
"Frankly, I don't know why the boards were killed -- I didn't do the initial handiwork (changing them all to "dead").

But, since they were killed anyway (which was something I was planning to do eventually), it seems like the best time to formally put an end to them. They were at best marginally useful, but for the most part an embarassment to the project.

I will not mourn their passing".

From AaronGiles (again) in answer to, 'What was the REASON though'?:
"Let's see, could it be that....

Nobody updated mame.net anymore?
The site was falling apart?
It had tons of outdated information that just confused people?
The FAQ was years out of date?
The artwork was old and didn't work anymore?
The samples were outdated?
The WIP pages hadn't been updated for years?
The Links page was full of links to dead and/or dying sites?
Almost every page had a link to EasyEmu, which hasn't been updated for 2+ years?
The download pages still made love to DOS like it was a platform the devs cared about?
The forums were a disaster, barely moderated, full of useless ranting, spam, and regular newbie beatings?
The google ads on the site continually advertised for ROM sellers?

I mean, come on. The writing's been on the wall for years. Wake up, people. This shouldn't be a shock to anyone".

-Trebor

More posts at link above.