The commute issue is magnified by the various mergers that have taken place through the years. I will present one such case scenario which is no longer much of an issue due to retirements etc: Delta buys and absorbs Northeast Airlines back in 1972, a Boston based carrier that in its final days flew primarily from New England to Florida. For many years, Delta operated a BOS pilot base, but that has long since been shut down. So those ex-Northeast pilots tended to commute to JFK/LGA, ATL or CVG in its heyday. As the years went by, pilots who had been flying FH-227s into Lebanon, NH or Portland, ME climbed the seniority ladder and found themselves in the left seat on TATL flights ex-JFK. As I pointed out, those pilots commuted from BOS, leaving their suburban BOS homes by 10AM for a noonish flight to JFK or LGA from BOS. If LGA, then a taxi to JFK. They would crew a flight to Europe. The plus is that they only had to do this four or five times a month. This group of pilots has dramatically decreased in numbers in recent years due to retirements.
I do not know what other mergers have led to pilot base closures over the years due to merger and base consolidation. But it has to be a factor in the need for pilot commuting.