I think as far as delivery to the food bank, the people who are available and don't have to be at work (or any obligations) during the specific times are going to carry the brunt of the drive time. This is voluntary, and should be understood what their role when they sign up, but they can certainly decline if it's too much for them. This is a division of roles. I am happy to contribute food items and necessities, but unless this food bank is open and available to accept delivery at odd hours, I'm not the one to do the driving.
Donations are also donation of time. My life may be to hectic to deal with the time, but I can donate in other ways.
I think fussing over home cooked versus store bought is petty. I do think there needs to be a level of "rules" on what is expected and some "even-ness." I admit, if I spent my afternoon baking a casserole or if I went and spent money on something ready-made, I'd be pretty peeved when someone else plops down a couple dinner rolls or some mystery in a pan that has been in the back of the freezer for a couple years.
If you can't fullfill a certain requirement, for whatever reason, you really shouldn't sign up for it.
Some people are going to have more time and money to work with, while others are not. I think your church can work something out that people can contribute something useful, even if they don't have the same means as others in the group.
For the other contribution, it was not used in the manner you intended. It got shuttle-bussed and used in a different way. I can see your annoyance, but at least it didn't get tossed in the trash. I think I would just not contribute or be okay with the fact that the item was used and enjoyed, even if it did not get used in a way you intended. Store-bought items are going to have a longer shelf life, and are the items that are going to be saved for later if they can't be used right away. Home-baked and home-cooked meals, salad, vegetables, and fruits. are going to be used first since they spoil faster.
One member of the group has refused to bring food anymore, citing the fact that he is tired of feeling like his contributions aren't "good enough."
Bottom line, it seems there's way too much nit-picking going on, and I think I would just quit trying to contribute at this point as well. I don't have a whole lot of time and money to work with. I'm not the one who can put out best and fanciest donations. I would like to help wherever I can, but if I'm constantly met with "not good enough," I think I'm just going to step away from this one.
I don't think you are necessarily being petty, but there is some petty-ness happening here as a whole. I think you need to establish your own comfort zone and be satisfied with your choices.