I'm the anomaly that rob pointed out in the comments, so I'll weigh in.
As far as I'm concerned, any rep above 25k is fairly gratuitous, given that there are no more privileges to be earned (despite some excellent proposals for the 30k tier), and it might as well be spent constructively by awarding bounties:
- To incentivize the right types of questions, i.e. the types of in-depth, well-thought-out, highly non-trivial (but still within the realm of the answerable) questions that, because of a narrower subject matter or some other factor, are less likely to attract upvotes or answers.
- To reward the highly-detailed, high-quality answers that we all wish got a ton of votes but (again through e.g. a narrow subject matter) don't.
- To give users with a record of high-quality community moderation and content a faster access to the moderation privileges that will make them most effective at helping this community succeed.
And, since participation in SE is easier to keep to a high standard if you gamify it (at least for me), I decided to make a Data Explorer query to have some concrete numbers to focus on:
One thing I find very striking from that query is that there are a full fourteen users who have spent upwards of 80% of their rep on bounties: not a huge fraction of the site's userbase, but those users still deserve a lot of recognition, particularly for the ones who give out a substantial fraction of those bounties to questions by other users.
What I don't see in that table, and would quite like to see more of, is a larger population of the >25k rep userbase, for whom moderation privileges are a gone pursuit, and who have enough experience with the site to have well-defined ideas of the types of questions, answers and users that really make a difference, as well as the reputation to reward them.
In informal conversations on chat, I have tried to prod several high-rep users into making bounties more of a regular habit, and the responses have largely been along the lines of "I don't often find posts that fit those kinds of criteria", to which my answer is roughly: that's rubbish. If you're on the >25k rep side, it's almost a given that you spend a great deal of time browsing the site, and if you keep an eye to the ground with the question "what questions, answers and users really make a difference?", it won't be too long before one of those turns up on your path. When that happens, just click that bounty button!
And, in closing, I'll allow myself one bit of gloat: I'm planning to hit 20,000 rep offered in bounties with my 100th bounty in a couple of months. I hope to see more high-rep users on that leaderboard by that time ;-)!