Now, LSRR is _expensive_. Modern routers handle packets with options in hardware, and doing IP options in hardware is not cheap.
Conveniently, not very many of them are sent.
(BTW, what other options are actually used? :) IMO, prohibiting IP options altogether would be a good idea (and don't ask me about fragmentation).
I use the timestamp option sometimes. And the record route (no source routing) option. I do suspect that I'm one of a very small set with respect to the former, however.
As for debugging routing - isn't it much better to ask OFRVs to add remotely accessible traceroute servers to their boxes? There is no engineering or economic justification for diagnostic fucntionality like LSRR to stay anywhere close to the fast packet path.
While this might be nice in theory, I think that it would be a political nightmare to deploy. Thus leaving us with the status quo. It also has nasty state implications. --jhawk