How to explain to my supervisor that her style of input is hindering my progress?
There are several intertwined issues here, and it is going to be difficult to sort them out:

Your supervisor is an expert.  She likely knows things you don't.  So if you suggest one way and she suggests another, it may be because she has seen that way tried before and knows that it doesn't lead anywhere.

Your supervisor doesn't seem to be great at leading, or doesn't recognize that you are not her colleague yet.  If two people at the same level are trading ideas, shooting them down or poking holes to patch can be a very useful exercise.  As a new researcher, you aren't at this level yet, but she may be treating you as though you are.

What you consider interesting and what she considers interesting may not overlap

What you consider interesting and what is actually publishable within the scope of a single paper or blog post may not overlap.


Let's treat these individually.

I have seen many grad students (and I have been one myself) who don't fully grasp the field.  I've read papers, thought &quot;Oh, I can fix that problem&quot;, then gone on to work for a week and then find the paper written 20 years prior that solves it.  She has a much broader understanding of the field than you do, and she knows what's been done.  Take her suggestions helpfully: &quot;I want to do X, but my supervisor suggested Y instead.  I'm going to compare and contrast the two methods in a literature review and see which is best&quot;.  That's your job as a PhD student anyway.

This is time for an awkward conversation.  Depending on your personality, I personally suggest being a bit blunt but polite.  Tell her what you told us: &quot;When I suggest something and you change it, it takes my enthusiasm away.  Can we work together to make sure that my ideas are fully explored, even if they aren't the best?&quot;

This is up to you two to figure out.  This is more fun.  Ask her what she thinks the big problems of the field are, why she's in the field, what interests her about new research etc.

My supervisor was phenomenally good at writing.  I am not.  He was also very good at focusing a paper onto the key relevant points.  I was not.  We fought over papers a lot, to be honest, and to be equally honest it was a mutual problem.  Both of us had reasonable ideas, but he was better at it and knew what it took to get published.  I did not.


If your supervisor thinks that you are proposing something too broad, that's a very, very good indicator that you are.  Think of those broad ideas as your research program, and the individual smaller ideas as your research projects.  Projects lead to papers, programs lead to careers.  Don't take it as &quot;this is a useless idea&quot;, but more as &quot;this is not suitable for publication because you haven't actually solved the big problem.  You have, however, solved a smaller problem that moves us towards the bigger solution.  Let's publish that and keep making progress&quot;