It's because free market capitalism is the mortal enemy of progressive socialism. You can't set up a system where central authority takes care of your needs if you've discovered how to take care of your own needs. So they have to reject and combat everything that promotes free markets and free market capitalism. They must constantly paint the picture of the free market capitalist as a greedy rich SOB who is taking advantage of others. They attack the success of free market capitalists and label them as greedy and obsessive.
It's like having a garden where you go out each day, ignore the plants and everywhere there isn't a plant, you plant a weed. Whenever a plant dies, you replace it with a weed. Pretty soon, you point the garden filled with weeds and proclaim that gardens are a stupid waste of time because they don't work. Just look at all those weeds!
I tell liberal progressives all the time and they simply don't believe me... I have literally had three times in my life where I didn't have two dimes to rub together.... totally flat broke without a pot to piss in. All three times, I rebuilt my wealth through free market capitalism, hard work and dedication. It was difficult sometimes but it wasn't THAT hard. The crazy thing is, once you've done it, it becomes easier the next time because you know you can. We constantly get bombarded with these "hard luck" stories about these "poor people" who can't get ahead... can't do anything about the unfortunate condition they are born into... being poor.... but they CAN... that's the thing. But it doesn't happen by sitting on your ass feeling sorry for yourself, it takes hard work and dedication.
99% of success is your attitude! Has nothing to do with how much money you have or opportunities you're presented. It doesn't even have anything to do with education or access to resources. Success is almost entirely dependent upon attitude. The proper attitude can overcome almost any obstacle. Unfortunately, the only way this is possible is through a vibrant free market capitalist free enterprise system. The progressive socialist can't have that... it's too much of a detriment to their ideology. So why is the progressive socialist ideology so important? It's about power and control of the individual.