Dragon Ball Z Abridged makes an excellent point...

[Naught Esquire Boy]

What was the point of Guru unlocking Krillin's and Gohan's potential?
The pair were already strong enough to deal with the mooks on the planet.
But the power up didn't bring them anywhere near the level of the powerhouses on the planet.
According to Daizenshuu 7, Gohan's power level after the power up was 14,000.
He wasn't even strong enough to face Vegeta if he hadn't received several Zenkai.
So... what was the point?

[Seisele]

to try and make them feel important (mostly krillin)