I was wondering why someone could not put a bounty on their question here on meta. Is this by design or has the community decided that it is a bad idea? Because, at SO you can put a bounty on a meta question. I think it would be a good idea to have the ability to put a bounty on a meta question because that way the question, if it is important to the OP or the OP believes that the question warrants some discussion then can be brought more to light. For example my question about why bounties cannot be increased while a bounty is in progress.
The answer to this is that there is no reputation system on this Meta site to award bounties, and therefore considered by-design.
Bounties are only meaningful in an environment where reputation is available to be gained and distributed (through voting, but also bounties). Here on Meta, it does not exist. In fact, your "reputation" on meta is equivalent to your reputation on the Main site (with a mild delay in during a reputation-frenzy).
On the left is a view on Meta, while the right shows the Main site reputation:
Note that on Meta, reputation is substituted for "votes" (that does not have a hyperlink). It does not really give a tangible answer to the question "How cool am I?". Badges, on the other hand, is perhaps the only measure of comparable awesomeness, with some distinction in their availability (see Badges on Meta vs Main). Somewhat interesting to note is the availability of Mortarboard - a reputation-related badge - already obtained by some members of TeX.SE:
Meta.SO is entirely different, having its own reputation system in tandem with SO, and therefore allows bounties (and reputation loss from down-votes).