Although it's a partnership, I disagree that my feelings toward it are irrelevant. I'm here because I care about the quality of my work, & because I want full ability to promote it effectively. Right now, it feels like I'd be making tradeoffs if I go with either trade publishing or self-publishing.
99% of this can (most likely) be automated. If Amazon can do this, there's limited reason to think publishers don't have the ability provide unofficial sales data in a timely manner (I expect it to largely be a one-time cost to establish the right processes). It's really just good business sense to do so, to tell you the truth.
I apologize for my brevity here - I was typing on my phone and trying to get a lot out.
What I meant in saying your feelings are irrelevant was simply this:
This is currently the way the industry works. You may disagree with it. You may prefer to look for publishers who go against the industry norm, or you may prefer to self publish. Whatever works for you. How you feel about it makes no difference to the majority of publishers, whose business model is currently working for them, and who have a wealth of incoming new authors to choose from. How you feel about it makes all the difference in the world... to you. Not to them. It doesn't hurt them one bit to not get your business.
And yes, a lot of that can be automated, and I believe you're absolutely correct, it's likely the cost aspect of the initial set up for most publishers to do. There are other factors as well - business models, profit/loss info, etc. Would it be ideal if they could give writers access to the raw data? Yep. Will they do it? Eventually, I'm sure more and more will.
The publishing industry as a whole is changing, drastically. It's a constantly evolving machine.
As a writer, you need to find the path that makes the most sense to you - and the things you take into consideration when deciding on that path will be very personal. What's your personal business model, and can it be supported by a trade publishing house?
If you're really uncertain, and you honestly have not made up your mind, try querying for an agent. Or try querying direct to publisher (many of the big houses won't accept unagented submissions, but smaller ones often do). See what kind of response you get.
If you get requests for fulls, you can either accept and see where it takes you, or you can take that as a sign of potential and decline in order to self publish. I see nothing wrong with taking it to that point. If you want to go further than that, and you're still unsure if trade publishing is right for you, make sure to discuss that before signing on with the agent. That should be a negotiated part of your contract with them.
Either way... best of luck!