It's most likely from the sheer amount that suppression had increased from the Saiyan Arc. Against Raditz, it wasn't really treat as a major thing and the only difference seem to came from charged Ki attacks. Against Nappa and Vegeta, it was still at the point where the characters were at most lowering themselves to about 50% of their true power. This is a far cry from how much they'd improve on Ki control on Namek and onwards with Goku going from 5k to 60k or more in an instant before scouters could even register it or Piccolo going from at best not much above the Base Saiyans to SSJ tier, clearly a whole different ball game than what Gero had dealt with prior.
