If someone spends $1000 on one domain, it costs them $10 per year to hold onto. After ten years, they're in for $1100.
If someone spends $10 each on 100 names, it costs them $1000 per year to hold onto. After ten years, they're in for $10,000.
It's considerably cheaper to invest in fewer, higher-demand names. Especially ones that have been vetted by the process of an auction, imo.
One rock-solid $1000 name is also a lot more liquid than 100 much less desirable names, at least I would imagine so...