Even Ontarians don't speak kindly about wine from Ontario lol
Spend some time at wineries on the Niagara escarpment and you'll find some great wines, especially whites that benefit from the limestone heavy soils. Even the large producers that have a poor public reputation for quality (Trius, Iniskillin, etc.) have much better wines available on site that never make it to the LCBO. For the most part (some exceptions), the people who run these wineries are wine enthusiasts who genuinely care about quality. Prices for that quality are higher than other wine regions with more favorable climates, higher production, and lower labour costs though, that is true.