You can insist people don't wear thick gloves if they are handling your bees -especially if you are not charging them for the pleasure!
But what would your reaction be if one of these people then keeled over in front of you, as I did a couple of weeks ago, then say that it was your fault because you had insisted they didnt wear what they thought was appropriate protection?
Not being diliberately awkward, just giving you a scenario that could very easily happen.
If you arent comfortable with the way people dress around your bees maybe you need to go through other peoples colonies with them?
Providing people take sensible hygiene precautions, I have no problem with new beekeepers going through my colonies. They will soon find out if they are squashing bees, thicker gloves dont give invincibility! (And I'd shout at them!)
Also if you don't keep bad tempered bees, even if they go queenless or the flow stops and they get grumpy, they don't turn into stingers. I am not macho. I am not even that brilliant at handling bees... it is a learning curve isn't it.....but as I have got fussier about only keeping gentle bees and have been mroe careful not to squash bees, beekeeping has become calm, calm calm and stings are rare.
EVERY colony has potential to turn into a dangerous stinging mass of bees, for reasons sometimes totally inknown to us. People who think this can be stopped are in my experience just waiting to be humbled.
If anything colonies like this are the ones that cause the most problems, with safety becoming lax, or complacent. The beekeeper who has had them for years comes along just to look at the entrance to see how they are doing, or lifting the roof to look at the feeder etc, and gets the worst attack of their lives.
Trust me the only thing predictable about bees, is that they are unpredictable!