A couple of things here.
1. In Thailand's Muay Thai you can't just "appear unphased" by kicks and knees, and nullify points. Kicks and knees to the body hold the additional "score" of showing control over the body center, just by landing. This is different than punches, which require the physical and psychological effect for score. Yes, by bluffing no impact from kicks and knees you minimize the score, but these are still points against you.
2. It really depends on what you mean by "passive". You need to know what the score is to read the behaviors of both fighters. Thais, traditionally, once they have the lead, retreat and "protect" the lead. This can be read as lacking in aggression by westerners, when in fact this is often pulling away in the fight. If a fighter who is behind in the fight starts marching forward, and throwing a lot...but not having a lot of impact, this fighter would be seen as actually falling further and further behind. They are "chasing".
Sharpness in technique does really matter though. It shows self-control, control over the fight space, balance, timing. If you are truly displaying dominance over the fight space, then this will score.
I can't quite picture the fight engagement you have in your mind here, but if you are checking kicks and avoiding knees, and landing impactful shots, you should be winning the fight...though that also has to be put in the context of who is advancing, who is retreating, and what the score of the fight is.