I usually don't chime in on discussions like this, but here I go.
First on the Frontier aspect...I agree with above, you can't expect them to call every piece/item out...thats just not realistic. Part of this is also because I know what its like.
I am a big user of both blueprints and TMTK items in my parks. I wouldn't be able to do the work I do, in the time I do it, I didn't use stuff others put out there to share.
I do make an attempt to call out specifically where items are being used when I can. I do miss some, or even miss many all the time. Why? Because as I load items from the workshop, its because I like them when I see them at the time. My library of item is in the thousands right now and growing every day.
Its virtually impossible to keep track of all these items and who created them. It would require a huge database of sorts. So I do the best I can. If anything I do call out that most of the work is not my own and don't claim it as my own, but to thank and call out every creation...reality check...not going to happen. I do try and spend hours going back through my library trying to figure out what I ended up using and then trying to track it down in the workshop again to find the contributors details...and I have to say its very hard and takes a lot of time. I might recommend that if you want recognition easier, then include your name in the name of the item.
I post some of my work out there as well. I don't do it for notoriety, nor should anyone else. The workshop is to openly share and let others gain the ease of using pre-built stuff. Just because people are not liking, or not making a concerned effort to say so publicly about your work...doesn't mean they don't like it or its not appreciated. Just look at your download numbers as that would be a perfect indicator if your item is liked or not and should be good enough to serve any ego high you are looking for.
Honestly, if you are posting work and getting hurt about the lack of positive comments, then I would recommend to not post any work. Please don't expect or hold the community in general responsible for the recognition of the popularity of items posted.