I was paxing on DJ home the other day and two flights were combined due to u/s aircraft. At the boarding gate, the announcement came over that due to the full flight, the overhead lockers were going to be full so if anyone wanted to check their bags into the hold, they were welcome - and no charge would be made.
At least 40 people went to the counter with their overnight wheely bags and were happy to send them below.
Based on that observation, I'd say it's the cost, not the wait at the other end that does it for most people.