wow, only one top-level comment on the first page of comments... Maybe HN should load all comments minimized by default, and only load them when you expend them.
I'm aware that there are several enhancements to comments display and especially large-thread display, in the works. Yesterday's load-induced outages were probably related to this.
More graceful presentation of large threads is something HN could improve. It's a hard-ish problem, though there've been some elegant solutions elsewhere.
Kuro5hin progressively auto-collapsed threads as size increased. K5 itself is dead, though the Scoop CMS it ran on still has a site up and the behaviour can be seen here: http://www.scoopdev.org/main (Go to a discussion, toggle the display mode between Threaded, Nested, Minimal, Flat, Flat Unthreaded, at the bottom of the page, JS required.)
On Reddit, the default UI accepts a "?depth=<count>" argument, which can make large threads more readable. Reddit Enhancement Suite has a "hide all child comments" feature.
(I've forwarded your suggestion BTW.)