Its unfortunate what the market has turned into and its not only based on your observation but what is currently happening. Today I see a lot of adverts all over in various public forums and groups with captions like 'get bitcoin for free by joining airdrops' all they need to do is register get the air drop the convert to bitcoin and cash out. This is not only leading to lots of capital flight in the market but also damaging its reputation because any venture that you don't have funds invested and some amount of risk attached, for all you care, it can collapse tomorrow.

I think the beginning of this is because of the advent of forks all over and the ability to create tokens from ETH without much effort. This give developers the room to get the popularity they want without having to spend a dime and cause people to either vote or asked the coin be listed on an exchange market and that settles it. But I am hope that this will pass too as anything free is just going to be ephemeral. There is no need to lose sleep over it.

if there are no airdrops, is there another way to attract investors and burn altcoins that have no value in the market?

your solution is good, its purpose is to maintain altcoin value in the market. but you forget, that you do not give any other ideas as a solution to the problem!

Can't agree with you. Airdrops are beneficial both for the noobs who get the coins for free, and for those who invest in the currency. The noobs get free money, while the serious investors benefit from the price rise, which will naturally occur when the user-base expands as a result of the airdrop. And not all of those who receive airdropped coins dump them right-away. Most of them keep at least 20% to 50% of the coins for long-term.

A Airdrop is a good thing, if it was funded by the developer of the coin and not funded by some pre-mine. The pre-mine is just an excuse to give free money to the developer and his/her buddies. I am also not a big fan of the free coins that are awarded to people when there is a fork. <like BCash / Bitcoin Gold>, because I am a strong believer that people have to work for their money.

Take Ehtereum for example : There was a pre-mine and most of those coins went to the developers and the founders.  

That's true that some people ruined it by dumping but you should consider the benefit of Airdrop. Airdrop is an easy way to spread a crypto among the crowd.

Because most of the new people who are now registering in the forum are from poor countries that have no starting capital, they have no jobs, didnt graduate from a university or from college and no career prospects.

That sounds bad, but its a fact.

Wow! What? Any link to this? That would be really really huge, majority of my portfolio is in Electroneum...

Read the project KYC.Legal. I find it very interesting.Service that allows to verify users and to prevent fraud. It is based on blockchain technology as a tool for protecting and validating personal data of Internet users. This project already has its own product and it has no competitors.

experty.io and cardstack，As we all know, bitcoinsuisse is a very strict website, and the projects above are generally good projects.
https://cardstack.com/
https://www.experty.io/
This is their website. You can try it. In particular, cardstack, which hasn't started crowdfunding yet, but this project I personally feel very promising,