I see what you mean, but I think that @lottobot's system is pretty unique on the Steem network, and that might contribute to the (small) popularity that it does have so far. Dividing up the value of the vote is pretty similar to the way bidding bots like @lovejuice, @bellyrub, and @booster work, for example. The winner-take-all lottery approach is pretty different from that and fills a good niche, I believe.
As for popularity I am actually pleased with the response to @lottobot so far :) Today marks a full week that the lottery has been running, and there are already a few regular users. I truly believe that exposure is the main issue facing @lottobot now. This article has just over 200 views so far, which is not that many. I think @lottobot will see more use if and when a higher percentage of the network knows about it. That is why I like services like the one you offer :)
Also, @lottobot is still under active development (I am actually going to make a post about its development pretty soon). It has some upcoming features that I will be able to talk about pretty soon that I think people will be quite enthusiastic about. That will be coupled with increased delegation in the future.
Thanks for your interest in the project :)