matthew16

I appreciate the response, but it is a limitation. 
 
Of course it may slow down the query. That should be something the user is responsible for managing. 
 
Advantages of script filters showing up in the default search:
 
significantly more flexibility and power of workflows Complete control over what shows up in the default search Ability to include all searches. For example in my case, Pinboard Bookmarks. This is very important for me. Ability to customize default results by replacing them workflows. It is not a hindrance to the user:
100% optional. Imported workflows that want to be included in the default search can be dealt with in a variety of ways, such as: A warning alert that 'This workflow wants to be included in the default search. This could slow down every query, but can be turned off later. Proceed?' And it can have three options: 'Cancel', 'Import without including in default search', and 'OK'. In the 'Features' pane, there can be a new list of workflows that are included in the default search. Each will have a checkbox. At the top, there can be an off switch for disabling all of them at once. I believe this will in many cases not slow down the system at all. Has the team tested this? I find it hard to believe my computer can't handle this considering how much it does already. The user already has to manage performance anyway.  
It would be beneficial to Alfred and the community:
 
We would probably see an increase in participation and contributions. Alfred can take ideas from these contributions to further improve the product. It would be a Powerpack feature, giving user more incentives to buy. $$$ I don't think it would be difficult to implement:
As far as I understand this is just a simple restriction and would not involve any large changes. The only problem that would need to be solved is deciding how to order the results. I'll throw out some ideas, but I'm sure this calls for further discussion: Integrate them into the same algorithm based on past actions. Put them at the bottom or top of the results, with a border distinguishing them from the default results. In the workflow give options for how the results should be sorted relative to the default results.  
In conclusion, this would not affect the average user, would give 'Powerpack' users much more 'power', and is a positive step forward for both Alfred and the community.

@matthew16 While it's not possible to exclude the contents of a folder as such, you could create a file filter workflow that exclusively searches for folders, which means that while folder B would show up, the documents and files stored in it would not, making for a tidier search.
 
Here's how you can create a file filter workflow:
https://www.alfredapp.com/help/workflows/inputs/file-filter/#workflow
 
Instead of searching for PDFs, you'd drag in a folder to search for folders only. You can also set the scope if it's relevant
 
Cheers,
Vero

I personally use Alfreds file search in combination with the "Quick File Search Mode", but i've made you a small workflow that let's you select
a file/folder to create a alias for and then a folder where you want it to be saved to.
 
Here you go(I assume you have Alfred 3): https://www.dropbox.com/s/g4clxs0pmy7p14l/Create%20Alias.alfredworkflow?dl=0
 

I think this has come up before but it's a great idea.  Alternatively the keystroke for Alfred Preference command-, could just be context-sensitive.

alfred-nodejs-tools
This Alfred 3 Workflow includes some useful tools for node.js developers:
node ls: List NPM top-level packages. List packages for current default node.js installation (regardless of whether is managed by NVM or not). node nvm ls: List all NVM installations top-level packages. List top-level packages for all node.js installations managed by NVM. node nvm install (new-version) (old-version): Install a new node.js using NVM. You optionally can select an old version to reinstall packages to new version, or use none to skip this part. The list of available versions is automatically pulled from https://nodejs.org/dist/. To download and to view the license see the following GitHub repo: https://github.com/xrubioj/alfred-nodejs-tools
Enjoy!