They sold for quite a bit more than $1M, in fact. I would argue that the actual sales are realistic (in the sense that they reflect the actual price that people are willing to pay for them, i.e. their actual value), and it's merely your expectations that are unrealistic. You are significantly underestimating how valuable a good one-word keyword is in a single globally unified namespace used by billions of people daily. For companies worth many billions of dollars (most of the below), a few million on a killer domain name is nothing.

Here are some notable expensive domain name sales:

    Uber.com     2% of the company's equity in 2010 (!!)
    Sex.com      $13M
    Hotels.com   $11M
    Tesla.com    $11M
    Porn.com     $9.5M
    Fb.com       $8.5M

https://en.wikipedia.org/wiki/List_of_most_expensive_domain_...

An asking offer without a bid is just that - an offer. I can ask $1M for that red apple sitting on my desk. It's completely irrelevant.

PS. This behavior is quite prominent in real estate prices, they're so slow to fall down. For example the US real estate market bottomed only in 2011. You have to be very patient if you want to buy the dip in such "I will only sell for the right price!!" markets.

You'd be surprised. Not going to name anyone in particular but I know of multiple major one word domains that have been bought for that order of magnitude (some more, some less). For certain companies, that's chump change compared to the additional traffic a good domain name will bring their business.