Because colonies had little money to invest in industry.
I’m not sure if you have specific countries in mind but here are a few countries created after the Ottoman Empire collapsed;
Turkey
Armenia
Iraq
Syria
Lebanon
Israel
Palestine
Jordan
Saudi Arabia
The countries above were either under full Ottoman control or suzerainty.
Hope this helps :)
Answer:
Europe saw the colonization of Africa as an opportunity to acquire a surplus population, thus settler colonies were created. With this invasion, many European countries saw Africa as being available to their disposal.