When I first started visiting wineries 30 years ago in Napa and Sonoma, the tasting rooms were just tasting rooms. Sometimes they'd have a few souvenirs, such as wine books or corkscrews, some had informal picnic areas or did a little side business hosting weddings or other events, but the business was really all about wine.
Over the years, those side businesses have evolved to be the primary business at some places. V. Sattui, for example, is a deli first and a winery second. Viansa was built to be primarily a deli and gift shop, and doesn't seem to be competing in the wine business any more. Ledson is a blatant tourist trap that charges for tours if its phony "castle".
Any other places like this to avoid?