Because Wiktionary does not enumerate all possible affixes on a verb.
Bob Cromwell for example (following Lewis’ grammar) enumerates the following possible verb modifiers:
- negative
- passive
- causative
- reflexive
- reciprocal
- eight tenses
- six moods
- two numbers
- three persons
Of these, Wiktionary is counting:
- negative
- five tenses
- two numbers
- three persons