I like a lot of quiliting. FMQ is my favorite stage of the process, and it's where I add my own personal vibe to a quilt. It's not just about structure -- it's adding texture, secondary design, and subtle color additions to the pieced work. I think when it's done purposefully and and with some skill, you can't over-quilt. Not saying that every quilt ever can support heavy quilting. A case in point -- I'm working on the 365 quilt block challenge -- lots of tiny blocks heavily pieced, and that quilt is all about the piecing, so the quilting will have to take a backseat and be more structural rather than a design element in itself.
Those who love to go on about how stiff and cardboard-like heavy quilting makes a quilt -- that's a problem of not using the optimal batting type and/or an unfortunate thread choice more than a density of quilting issue. Sometimes too there is an element of sour grapes that sneaks into those comments. I get it somewhat -- before I had the ability to do FMQ myself, I claimed to like stitch in the ditch / invisible quilting. That's what I felt was attainable on my equipment and with my time and skill set, so I didn't really key into FMQ as an art in and of itself. With a machine upgrade and some time devoted to learning how to do it, I love it and really admire and appreciate the masters who share their work and tutorials online.
I think it's sad that quilters seem to think it's fine to be rather rude about heavily quilted work -- or dismissive with broad strokes, while they would be outraged if similar comments were made about under-quilted work. There's a real double standard for the level of rude that's tolerated in comments about quilting. What ever happened to just saying "I really like doing it this way because I think it looks best or works well for my skills" and leaving out the negative comments about the opposite>