The first three groups may shy away if the price crashes, but the fourth group will (mostly) not. Because what the fourth group is doing (mostly) does not care what the price is.
They can buy their goods whether it costs 0.00001 or 100 BTC, because those goods are indexed against fiat prices. As Bitcoin goes down, prices on the markets that sell these goods automatically rise to counter.
Perhaps the price gyrations would be more aggravating for the sellers of these things. They rely on converting cryptocurrency back to fiat to finance their business, (although perhaps some are able to buy their wholesale product with crypto directly). Volatility exposes them to a risk of losing value if Bitcoin falls between the point in time a buyer places an order, and the time the seller is able to withdraw and convert the payment to fiat.
Ultimately these buyers and sellers support some price floor for Bitcoin and other cryptocurrencies as they exchange real goods and services.
There's a lot of hype around cryptocurrencies, but ultimately this is the true killer use case. And there are millions of people who value that >$0.