I know it sounds simplistic, but after over a decade of watching Muay Thai, I feel in the big stadiums particularly (after the more savage golden era of the 90s early 2000s), even in the smaller provincial shows, it has been all about counting clean kicks and knees and also seeing which fighter can keep a strong stance/balance and wont turn their back away or fall to the ground(under any circumstance, whether its from a sweep/dump or from slipping themselves).
If you think about it, it makes it easier for the bettors to visually see who wins. They don't care about entertainment, they want to win money and the cleanest most obvious techniques you can see landing are a kick, a knee, and the other guy falling/stumbling. Muay Thai in Thailand is a sport steeply rooted in gambling, like cockfighting. There is a hierarchy to strikes and certain strikes/maneuvers are more valuable than others in the eyes of Thai judges.
For fighters, if you receive a body/high kick, you either dodge it or block it (with a leg CHECK, not your arms, using an arm block doesn't register as a valid block) and answer back, that cancels out the point. If you just take it on your guard and don't do anything or use an arm block and answer with a flurry of punches like a lot of westerners do, it isn't seen as effective and thus is a point against you. You could also catch the kick and sweep it away/return fire, or go for a trip/sweep.
From my experience/observations punches/elbows don't count for much unless you rock/cut your opponent or make him dramatically retreat or show fear/pain.
I love the sport, but Muay Thai is really its own thing. It's not boxing or kickboxing (both have many similarities in scoring/officiating).
Maybe the scoring can be compared to Tae kwon do, except with no protection, shin contact, knees, lowkicks, punches/elbows allowed.
If anyone disagrees with my thoughts on stadium Muay Thai I'd love to hear what you think.