Isn't it worse that TOS was inconsistent with itself? After all, there was far less material back then for them to have to review and make sure it was consistent. Hell, even when TNG started, all they had to review was 79 episodes and four movies. As opposed to today where there's 800 episodes and thirteen movies. If they couldn't stay consistent back when the franchise had fewer than a hundred episodes and movies total, why should they be expected to be consistent now when that number is within spitting distance of a thousand?
And besides, no continuing franchise has ever been that good with keeping itself consistent. The old Marvel comics were so bad at it they actually turned it into a game for the fans with the old Marvel No-Prizes. Doctor Who had a producer who actually admits continuity is only what he can remember. Why Star Trek fans exist the franchise has always been a bastion for consistency up until very recent, or that consistency even matters truly is a mystery for the ages.