Successful startup outcomes and solvency in the incubator world are not correlated well. The companies that are selected are carefully directed through a maze of expensive professional services controlled by the program directors. The bargain becomes... if you use this lawyer, this PR consultant and this accounting firm we will support you. What this means is that every failed startup isn't really a failure because in the end that company spends all their money paying off the incubator's network. It's an engine of corruption that takes advantage of people and companies that can least afford it. Whether they create any real startup success is not especially relevant to their continued survival, it's just a bonus.
Many incubator programs also tends to select for people who are very well behaved, polite and have simple A to B ideas. True disruptive innovation is usually created by disruptive people who have very big ideas.
I don't think incubators really intend to hurt founders or the market, but they do.