The reason it was bumped is that it was modified by the community user:
You are right that it was to get attention for an unanswered post. The algorithm is different per site, but it doesn't take the user's presence into account - likely for reasons already discussed: why does it matter if that user didn't stick around? If it was a good question, or at least not a bad question (as shown by the non-negative score), doesn't it still deserve an answer, for the benefit of the site and the community, if not for the original user? Also, remember that the asker may not seem to still be around, but he/she actually could be - they could be lurking, or using a different account (this is certainly common when someone has had a question migrated here).
I don't think we really have any control over this on our site, and you'd have to make a pretty compelling argument that bumping this post was somehow bad in order to make any changes that would make us special:
The Community user will bump non-negatively scored questions that have at least one answer scoring 0 and none scoring more than that. The number of unanswered questions bumped per hour depends on the site: 4 per hour on Stack Overflow, 1 per hour on Meta, and 2 per hour on Super User and Server Fault. The default for a new site is 1 per hour.
You can get more background here and here.