One day someone had the idea of exploiting that behavior to make profit from the "gamblers". So they first created a platform that allowed easy production of useless tokens that gamblers could make bets on their price and secondly they designed that platform in a way that these gamblers needed to buy that platforms main token (ie. ether) to be able to bet on those tokens therefore creating an artificial utility for their own useless shitcoin.
I agree that this was the outcome, but I think there are actually a lot of legitimate uses of tokens. (Not on the Bitcoin main blockchain, in my opinion.) ICOs started with the promise to "democratize" credit / loans. Everybody could give out a token and take a "decentralized type of loan" to fund their business. In theory it is a way to decentralize banking.
In theory 
Because of course that led to many scammers exploiting that mechanism and that's why ICOs and tokens in general today have a very bad reputation, and most of them only cater to "gamblers" as you call them.
I still think tokens are a technology with a lot of potential, what is needed is a better trust ecosystem. Tokenomics of major tokens and altcoins are a disaster. If a "better standard" could emerge eventually, we may see decentralized banking flourish some day.
As a side note, one does not need smart contracts to create tokens. There are much simpler mechanisms like colored coins. I'd actually like LTC to be used as a token platform for "serious" tokens. (There is Litecoin Ordinals but Ordinals is generally a crappy platform, there are way better mechanisms for tokens than that. RGB would be an idea, but afaik it still isn't supported on LTC. There seems also to be an Omni port, OmniLite.)