I’m on your side on this one. I wish more customers would be more fussy; if everyone were like you, technicians would do a better job the first time they come out.
I install automotive electronics for a living—mostly remote starters and alarms, but a little bit of audio, video, navigation, and whatever else you could imagine.
I make every effort to leave customers’ cars as found. That is, no wire clippings on the car floor (and also not on the ground outside the car), all panels properly reinstalled, and so forth.
I invariably listen to the customer’s car radio, and often have to reposition the driver’s seat and tilt steering wheel. When I’m done, I put said items back as close as possible to where I found them. If I can’t remember what station the radio was on, I at the very least will hit one of the preset buttons so at least it’s on a station the customer likes.
Anyway, leaving garbage on the ground is a guarantee that the “technicians” sent to your home are a bunch of animals. You should forgive one or two of those items dropped accidentally, but not what they did.
Same goes for leaving the plaster dust around. A good friend of mine is an electrician, and when he did some work here at my house, he came back in with a dustpan and handheld broom and cleaned up after himself.
And if you can see daylight coming in through the holes where they ran the wires, you can be sure that it’s an open invitation for water, drafts, and ants to come in. I know you mentioned wanting some kind of “plastic cover,” but I’d imagine the usual treatment would be to run a bead of silicone caulking around the hole. That’s what they did here (both Comcast and later Verizon).
Lastly, regardless of whether or not your expectations are too high, there’s no excuse for them not calling you back.