In bounties when it say token this will be a specific and direct payment from the campaign. This can be calculated and show the total immediately. While stake is also means of shares. There will be a formula to computing the number of shares value. The value of total shares is depends on the value that accumulated by the campaign until the end of campaigning period. So it is much easy to know the total earning that you can get when coins or tokens are their rewards in including every weeks of their campaign than to shares.