You can put a timer on scoring criteria, yes, so that they would reset after a period of inactivity, if that’s your goal. However, you would have to do this for each criterion. Otherwise, you would not know how much to subtract exactly to reset a contact to 0.
Another approach would simply be to substract more than needed. A contact might then have a negative score but would be easily identifiable.
Stumbled upon this thread as I was learning more about Hubspot’s native lead scoring capabilities.
There are good reasons to reset lead scores A. for certain leads (e.g. when a deal is lost) or B. for all leads after some time has passed from the engagement that increased the score in the first place.
Some 3rd party apps in the Apps Marketplace that do lead scoring may offer automatic resetting of scores.
Outfunnel for one offers lead scoring for Hubspot allows expiring scores after a certain period (see screenshot below).