I experienced the same issue, and used a workaround for it.
Option one:
Since the datamart has a sql endpoint you can query that endpoint. so you can add tables from the tables. As long as you do not recursive query your table it works.
Way of working:
first find the sql endpoint of the datamart: Workspace -> Datamart -> elipsis of settings (more options) -> Copy SQL connection string looks like [26char_hash-26char_hash].datamart.fabric.microsoft.com
now connect to that sqlserver and find the database name looks like db_[workspacename]_datestamp_timestamp_hash
Now go back and edit the datamart by adding data with Get data
fill in the connection, use your account to connect and select a table just for now anyone is good, hit transform data button
now the trick is you can eddit the sql query afterwards to replace the table you selected..
so hit the gear icon in the query settings and put your view query in the advanced options.
load it and you have a table. that works instead of a view, and it loads in the model!!
