What you are describing is not incubation, but rather "Venture Development" and is somewhat different from incubation, hence your confusion.
The glut of startups that the global tech movement is fostering, is flooding the field with fewer and fewer good ideas and less good plans, leadership and teams. That said, most startups today -- if they are worth anything at all -- have at least one of these elements going for them. The rest of the elements have to be developed by people with experience. This is where venture development comes in.
Solid venture development has -- at minimum -- the following components: (1) experienced partners (with a mix of successes and failures in every key facet of a startup such as business plan development, sales experience, finance and accounting, etc), (2) a deep and relevant pool of social and business contacts for board and staffing assistance, (3) direct access to individual syndicated capital from early stage through Series A, (4) a media network spanning both traditional and social media, with some in-house expertise in same.
Note that the venture developer is taking on more risk than an incubator, angel or VC, and usually plays both inside and (importantly) outside of the 'good old boy' network. Hence, there should be a minimal charge to startups to make sure that the FOUNDERS are fully engaged and not just appropriating resources and contacts. only to move ahead somewhere else after they get to the next level. $6k a month for a year is a bit much, but somewhere between 5k-15k, depending on the size of the startup, the goals and the amount of work necessary to get things started - is reasonable on a one-time basis. A bit of equity and back-end on successful funding is natural.
So, to answer your question: YES, there is a business sector rising to support and advance those startups that, by accident of birth or luck, or by the nature of their business, do not have the specific tools or access to engage with the more famous or traditional incubators -- or to get unicorn funding, which everyone dreams of. Venture development is a legitimate business and if done correctly, produces results that sometimes exceed traditional pathways.
My advice to you is to check the team that proposes to work with you. Have they been successful at least twice (anyone can get lucky once)? Talk with those successful founders. Do they have a demonstrably deep network with key individuals relevant to your space (especially finance)? Research those individuals. Is this group willing to roll up their sleeves and get into the trenches with you if and when necessary? Make it part of the deal. Do they take anyone, or are they careful and realistic about who they support (this is key)?
The point is you are asking them to be accountable to you, so do your due diligence. You are also asking them to place a bet on you, when you are missing key components of success -- expect them to cover themselves as well, so that they don't go broke trying to help you and others succeed.
The media gives the impression that there is free money dripping from the world's wealthy, and all you need is a pen, a napkin, and a concept. Nothing could be further from the truth and most find out the hard way. Most startups never make it to incubation, never mind funding. Venture developers help to create a rising tide that lifts all boats and makes the dream at reasonably more possible. The world will see much more of this model, so its something you'll need to get used to. Just be smart about it.