Aduana disservice at the airport.

We picked up a friend coming on Alaska on Saturday. She told us the flight was about 20 min. late so we adjusted for this. She also said a national flight arrived same time as hers. The immigration (one person) and then one person from the aduana (customs) checked her through. Normally, she goes through rapidly but she had to check her carry-on due to her toothpaste being too big. We waited at the airport for about 1.75 hours for her to come through outside in the canicula/dog days of summer. I thought, don't the Mexican immigration and aduana put more that one person each during the heaviest time of the week (Saturday)?