I know it is a potential trading opportunity, but you have to question the type of gap, e.g. common, exhaustion, breakaway, runaway. There isn't a 'one gap fits all' scenario.
So let's just look at the possibilities and draw our own conclusions. It isn't that big a deal to discuss and analyze gaps.
"There is an old saying that the market abhors a vacuum and all gaps will be filled. While this may have some merit for common and exhaustion gaps, holding positions waiting for breakout or runaway gaps to be filled can be devastating to your portfolio. Likewise, waiting to get on-board a trend by waiting for prices to fill a gap can cause you to miss the big move. Gaps are a significant technical development in price action and chart analysis, and should not be ignored. Japanese candlestick analysis is filled with patterns that rely on gaps to fulfill their objectives"