Unified identity would seem to be the most obvious reason to me. If your phone number was the same as your email and facebook (or whatever social network you use). It seems to me, though, you are actually making the case for numerics when you say "Chinese people pay a premium for 'lucky' phone numbers and license plates." -- because, exactly that. They've paid for their "identity" in this 200 year old technology -- did Bell ever picture that people would have phone numbers and even more that people in China would pay extra money for the specific number pattern their phone number had? Indeed... They'll also pay for premium online presence numerics as they progress forward (quickly) from that 200 year old tech into more modern times -- namely the times of the universally owned and immune from China's government: .com
At the same time, I don't expect them to all be used. And it was just recently that I realized one of the better ways to explain my theory on "longer" numerics (and 'longer' short L) as a currency is to consider that each is a unique serial number -- and it can be bought, sold, traded or used, while being limited in quantity based on length and quality. If people who like numbers could pick the serial numbers on their hundred dollar bills, they'd like pick them with a lot of 8's.
I could give you all sorts of neat theories. If BitCoin or cyber currencies go more mainstream, perhaps you point your 99888880.com domain to be your receiving wallet... and just like wanting to have a prestigious phone number or license plate, you want a "i'm the man" kinda of numeric.com. Out of 1,300,000,000 people, you've got a rare and limited five 8's name. You have to separate something like 99888880 from the likes of 31040695 --- follow from that to see there are NOT 100 million 8N people will "strive" to own; CHIPs top out at 16 million... and you can easily find smaller niches and numeric patterns that will be well sought after in 8N or 9N over a 7N like 3104065.
So, you could actually have a mix of BOTH people who invest in these and people who use them.
All that said, sure, absolutely... it's entirely possible there's a bubble in numerics. It's entirely possible after all is said and done, domains are just domains used for accessing the top 100 websites.
But it's just as likely that domains are growing in their role, rather than decreasing in it. Whether that be as an as yet un-regulated economy or true investment in a future of digital presences.
As for why pick up all the drops... The simplest answer I can think of is lack of originality and/or knowledge of how to script a search for available names. The drop lists are pre-created lists for miners. No thinking. Take the list and drop it into one of the handful of desktop drop catchers (where you don't pay anything more than the reg fee because you're just auto-registering without any auction competition). And from there if "someone" thought it was valuable over one of the existing hand-reg'able dotcoms, then perhaps it is. Do that en-masse in a market you think will accelerate in the future and you're bound to have more winners than losers. In theory, at least.
