Quite possibly. But there could also be other factors in play. One of the possible reasons could be the bayonet was made early or even before the war, and the rifle might have been made late in the war when production pressure (time/cost) meant many features and fine finish were dropped in favor of "it works, get it out the door"...
Japan is indeed a "blade culture" not a gun culture. That doesn't mean they deliberately made lower quality firearms due to lack of pride in what they were making.
Look at the pre war and early war guns, and you'll see their quality is on a par with European made military arms. Some of the Japanese designs are "wonky" but the quality of the builds isn't, until wartime pressure (and losses) forced them to cut corners.