For beginners in crypto world, their only goal is to gain much profit from investing a little. As a conclusion for your question why people are interested in altcoins, I would say the main reason why is money and profit, then other things comes out for transactions or gaming, shopping and many other features a token or coin can have and make a user interested in buying it.
In your case you want to invest just a little and gain much more than investing in bitcoin as a les volatile cryptocurrency, I believe it’s the same thing for every. Their interest on altcoins in about making money from smaller capitals, and I wouldn’t say it’s a bad thing unless you have to chose a trusted and legitimate project to creat their token and you invest in it with confidence.
The main reason why people are too interested to invest in altcoins is because of profit, their some altcoins thst good profit can be gained it it is not for altcoins, because of the profit that is why people are interested I altcoins, they believe I they buy low they can sell when the coin gains value. Despite that altcoins are very risky people still don't care on how they invest in altcoins, they just allow greed to control them to buy as much altcoins as they can.
If you have come across one of my topics, i said that the reason people invest in altcoins is because of quick profits, and i stand by that. They do not believe in the project, but they believe in 100x, 1000x, and even more. Unlike bitcoin, for which there are investors who are willing to hold it for a decade, have you seen anyone who is willing to hold his altcoin for a decade? Altcoins have low potential in the long run, and no one trusts them so much to keep there money in them.