Why don't writers use longer time skips?

Current Events

Squall28 posted...
Why is saying 5 years has passed between Part 1 and 2, harder to say than saying only 1 year has passed.

i'm guessing if the show runs for 20 years or it gets revived in 30 years(cuz you know, corporate greed), suddenly the protagonist(s) has to be 100+ years old for it to make sense if they kept adding 5 years whenever they wrote themselves into a time skip.
http://abload.de/img/pcgamingxtuvt.jpg
http://i.imgur.com/9Yv0R2Z.jpg