Sutter Home became extremely successful and we began learning about wine like you suggested. I think it's probably more about the era - early 1980s - than the particular wine. Today I suspect people are starting out and learning by buying Charles Shaw wines - "two buck chuck" - from Trader Joes.
White zin is still a good choice for a summer picnic if it's not too sweet. Roses and blush wines were the 'in' summer wines this past year. Sparkling roses, especially French, have been hot for a few years.