I am afraid you do not understand what makes an Open Source Project community. A list of bugs reported is not going to make people think you are a great mojoPortal programmer. I have plenty of Quality Assurance friends who can't build a framework like mojoPortal to save their lives. I do think a bug tracking system would be nice but we would need someone to manage it. Joe is very busy with improving mojoPortal as the Feature Requests forum gets a lot more traffic than the Bug Reports forum. To be perfectly honest, Joe does fix all the bugs reported so I am not sure that a bug tracking system would do anything except make you feel special by having a high number of reports. Honestly, I can't think of another platform of this size that has as few bugs.
I haven't checked this out or anything but I am confident that I am the most active community member in the Forums. I know I get a lot of traffic to my own site from mojoPortal and I can attribute that to my activity in the Forums. I am not trying to take credit for anything as I think Joe deserves the credit because he has built an enormously great CMS and given it to the world for free. Your experience with mojoPortal is confirmed by your participation in the Forums or development of modules. Take Dean Brettle as an example, he wrote the NeatUpload utility for mojoPortal and it is a very important part of the system. He isn't very active in the Forums but he is recognized by the community to be a mojoPortal expert in his own right because of his contributions.
As far as SharePoint Foundation 2010 goes, I think you will be very disappointed if you think that Microsoft is going to be as fast as Joe Audette is when it comes to fixing bugs. I am not going to compare SharePoint to mojoPortal because the two are not in the same category. SharePoint is primarily for collaboration and BI. mojoPortal is for building websites and web applications. Try skinning SharePoint with Artisteer or at all really, it is not for the faint of heart.
Regardless of your decision, I hope you do well. Maybe you'll be a SharePoint MVP someday.