You don't think they should be allowed to fire people for those first two? Those aren't even off-time activities, they are things that directly affect the work environment and the atmosphere/image of the company.
An employer should be able to fire someone for what ever decisions they make.
This includes their decision to smoke, dye their hair, drag race or be a homosexual.
Each are choices.
Thank you for the illustration.
BTW, just curiosity, mind: have YOU, personally, ever opened or run a company, any company (other than, say, a lemonade stand as a child)?
I don't accept the premise, at all. Evidently, you do. Excahnging one's labour for a wage in no effing way grants the employer any rights at all over one's otherwise lawful behaviour, specifically excepting general good order and productivity (sleeping on the job, clearly a no-no, for example), ESPECIALLY on one's own time.
If an employer should say, before the fact of employment, that you, the employee, can't do this and that and that and the other thing, whether verbally or by contract, then the (would-be) employee has no complaint. Accept the terms of offer, or don't take the position. THIS is the private company's privilege.
WHEN, however, such incursions occur after date of employment and without prior specification, the employer is in a purely false position, your nanny-statist protestations to the contrary.
Again, thanks so much (no sarcasm, not a bit) for letting us all know that you, personally, are (evidently) a disciple of Trotsky. This was one of his favoured hobby-horses to beat before EVEN the Sovs made him flee for his life.
Given his views, even his subsequent axe-murder doesn't seem too severe in retrospect.