Meme coin are a pump and dump coin. So I am not surprised if you say so because scammers and get rich quick actors are always ready to take advantage of the situation to makeore money from the newbies in the system. For sometime now it seems meme coin are taking position in the crypto market with good outcome from holders who kept promoting  it as a result of what they have benefited from it. Celebrities too who support and promote meme coin are another reasons why the meme coin are still doing much well in the crypto market.
 Memecoins do not waste time to grow very fast compared to legit altcoin which would require time to build and nurture to the final stage before it starts utilising it's potentials in the market. Just as you have said, legit coin takes time to be build as a result of the nature of their projects but memecoin doesn't need such as it is a hype type of work to gain attention of big names to aid in providing promotional content for which they would be of great benefit from.