Timing is critical in aviation, especially if it is to RV or deconflict. Get it wrong and the ultimate price could be paid!
Those who show consistently poor timekeeping should be penalised in order to make the point.
Put it to your Club, Smallpilot, suggest they penalise the latecomers and give appropriate discount or payment in lieu to those effected. If they're not symapathetic to your argument, explain that you are a regular customer and should be so rewarded. Depending on how strong you feel on the point, you could also (threaten to) take your custom elsewhere.
Good Luck!