You make a very fair point, we've actually discussed whether to introduce an "explode" button or not quite in depth!
The cons are the ones you mention: other powers are all "passives", so it feels a bit "left out" to have only one active mechanics, which we agree is kind of an issue.
At the same time, if things were to burn on touch, burning would be very similar to "passing the bars" mechanics-wise - also without having a "choice" button, puzzles (like the platforms moving on explosion) would be less about reasoning and more about action (not necessarily a bad thing, just a direction we took).
On a side note, introducing an "action" button was also reasoned taking into consideration other mechanics we designed, but which we didn't have the time to introduce in the final version for the contest T_T