Aiui Patrick read Larry Wall's 2001 Apocalypse #1 (http://www.perl6.org/archive/doc/design/apo/A01.html) and took it into account before he started Rakudo. It includes the following statement:
> "Multiple backends are a necessity of the world we live in today. Perl 6 must not be limited to running only on platforms that can be programmed in C. It must be able to run in other kinds of virtual machines, such as those supported by Java and C#."
That statement didn't require that any given P6 compiler be multi backend, but I would guess Patrick was thinking something like the following about P6 and Rakudo (first, my guess about his thoughts when he started it; then, about his thoughts a year or so later):
* Parrot would hopefully be a good host for a P6 compiler at the start and remain that way; OR, if not, it would evolve to become a good host (ie the convergence which you mention).
* After Rakudo on Parrot was "done", some P6 compiler, possibly Rakudo, would eventually be ported to JVM, CLR, and other existing VMs, as tuits and priorities allowed.
Later (2005?), as it became clear that Parrot was not a good fit architecturally for P6's / Rakudo's needs, he presumably responded. I'm guessing his thinking was something like this:
* Parrot and P6/Rakudo might sufficiently converge. This would avoid Rakudo having to focus, before an initial implementation was sufficiently "done", on porting. So Patrick should encourage convergence as best he could.
* Parrot and P6/Rakudo might not sufficiently converge. This would be an existential threat to Rakudo. So he should have developed a plan B. It should have been obvious to him that this would take several years and would best be avoided if at all possible, but he should have had a plan B.
Fast forward to 2009:
> "Putting Perl on JVM was always a kind of thought ... but was never really serious until summer of 2009 ..."
This is from the first minute of the video of Patrick's YAPC::NA 2013 talk "Perl on JVM". I found the whole talk interesting but the first 10 minutes are particularly instructive in relation to the things we're discussing:
https://www.youtube.com/watch?v=XgPh5Li3k4g&list=PLRuESFRW2F...