Create a view with a list of webform without any submission by current user
I'm not sure if there is a solution to create such kind of view using the Views module. But the Forena module (disclosure: I'm a co-maintainer) can be used for this type of reporting. More specifically by using its facility to create a Display of a table in crosstab format.

A crosstab table is a table with a special layout. It is formatted as a grid, with:


the rows representing one or more (combinations of) facts, such as countries or regions, names of persons (or users) like employees / salespeople (or user IDs / user names), etc.
the columns representing one or more other facts, such as periods (months of a year, years, etc), available types/flavors of something (like types of errors), etc.
the intersections of rows and columns containing the actual information (data), such as summarized information (counts of something), timestamps, etc. and which might (optionally) include a hyperlink to a drill-down report.


Below is a sample of such crosstab report (including drilldown links also, i.e. the numbers in red in it):



Refer to my comment in the Forena issue queue for more details about the above screenshot. And/or have a look at the video about How to generate crosstab reports with graphs (Forena also supports charting of those data, a typical related requirement ...).

Specific to your question here, I'd create such table in crosstab format with rows/columns like so:


The rows should represent your users (1 row for each user).
The columns should represent your webforms (1 column for each webform).


With such setup, the answer to your question is then contained in the intersections of all rows and columns that are shown as "blank" (= zero submissions of the specific webform by the specific user).

PS: I'm assuming you're using D7 ...