That post on Brickset did sum up things quite well from the challenge from LEGO, but sadly didn't touch on one misconception that LEGO doesn't care about the secondary market. To a certain point, it's true, since LEGO never makes a dime on a set when it balloons up in price, but there's also the side of trying to take care of collectors that have those sets on display. Like sparkart talked about with Weta, LEGO needs high-end sets to say "special," because that's what keeps people buying and investing.
Unlike the system line, where sets have a short shelf life, and the target market has turnover of 3-4 years (between starting to play with LEGO and then growing out of them), the high end and adult market has customers that are going to focus on it, potentially, for decades. And they cannot risk alienating a customer base that will spend 5x or more, on average, to get these items (price difference between UCS and high-end sets vs. system stuff you find everywhere). Releasing a redesign of something popular to that market could mean either a) they won't buy it because they already own one or b) they'll get mad and stop buying all together. For LEGO, that wouldn't be worth the risk.
It's also not as if this is something unique to LEGO. Collectors are terrible customers to cater to, and there are more collectibles than even a decent google search can reveal, and chances are, most of the people collecting something haven't been doing it their whole life, and had to come in late. Go ask some of the Transformers collectors we have around here (like half the staff... they're all nuts) on trying to get the old stuff. Same kind of thing here.
I came in to the Modular Buildings line late, starting with the Firehouse and Grand Emporium. I actually went out and built the Green Grocer from Bricklink orders. It took me months to finish, and honestly didn't cost me all that much less than just buying the set would have, but it was still fun. I'll do the same for Cafe Corner and Market Street eventually, but won't bother to complain to LEGO about not getting it back then, or even hope for a reissue. There's always something that was missed, and there's always something new coming out soon... just how life goes in the AFOL world.
You know, if I see links to Brickshelf, more often than not, the first thing I click is the "Back" button.