This is a great question, actually.
I've written all my life. And my peers, teachers, family, friends, etc., have always loved my writing. I've heard, "You should be a writer!" consistently for more than two decades. I've won awards and received a lot of local media attention for my earlier writings. Yet, I never pursued writing for profit. I was content being wife and mom, and I'll be honest. I was scared to pursue it.
Finally something clicked for me last spring, and I had a story I desperately wanted to tell. I wrote it out and edited it.
The novel I'm submitting right now got rave reviews from my test readers. They loved it. Cried over it, talked about it, swooned. I felt ridiculously confident that I'd find an agent somewhat easily. Ha, ha.
I sent out lots of queries with little to no response, and then I realized my query sucked hard. From more than fifty queries, I was asked for 2 partials and 1 full. (1 partial and full are still out). So I went to Query Hell and reworked my query. I also decided to take this month away, to relax, work on another book, and revamp my manuscript.
So, to answer your question, I think it is my query at this point. I was R'd on one partial, but I wasn't upset about it - I knew to expect differing tastes over my writing. I haven't rec'd any feedback on my full or other partial yet. The one holding my full just accepted my trimmer, revised version, for which I'm grateful because I think it's much better. The one holding my partial hasn't let me know anything yet. So I can't say that my manuscript is bad; I've literally gotten no feedback other than query Rs that say (if anything) "Doesn't interest me." No wonder, considering how unappealing my query was.
I think once I hear back from these agents holding, I'll have a better idea what changes I need to make if it's a problem with my ms. But to be honest, right now I believe it's my query.