Any average PM will tell you why it is important to keep your enthusiasm in control to finish of your current goals.
Yea, and any average PM would also tell you that in order to get some long term project done, you need to get people motivated. Most of (all?) the people working on Perl 6 does it just for fun, and they are entitled to do whatever they want with their free time and follow the path that betters suits their guts.
If you don't like that, start sending money to the project so we can change the motivation factor from fun to money. Or just contribute your time and do that parts that you thing that should be done now.
Otherwise, just shut up, please!