This scam market where they trade fake tokens called Ordinals is essentially the same as the altcoin/token market where from time to time we see a period of big pumps in a large number of altcoins. For example the 2017 pumps, the ICO mania, etc. The reasons are the same too.

The two important reasons for the temporary hype in my opinion are:
- Being new
Ordinals scam is currently new so it can attract a lot of people the same way ICO scam did in early days. In fact this is the main reason why they keep changing the name and coming up with a new one for the same garbage they sell people:
ICO, IDO, IBO, IEO, ITO, STO, DeFi, NFT, Ordinals

- Influx of newcomers
2017 altcoin pumps is the best example. When there are newcomers who don't yet know any better, they become the best target for such useless junk. They are the target of advertisement and they buy the junk with enthusiasm thinking they've struck oil and are about to get rich, specially when they look at bitcoin history (price went from $0.001 to $50000) and think it can repeat with the junk they've bought!