My tenant has been there for approximately 2 months, and the upstairs tenants have been increasing disruptive and hostile to my tenant.

Your only concern is the behavior which is disrupted to other tenants/neighbors and not in keeping with the legal mandate that tenants have the right to the peaceful use of the property. 

A high maintenance client can really disrupt your life and make you less productive -- especially if real estate is something you do on the side. 

My life would be upended with people coming into my space, my bathroom would be torn up for however long - when I would have rather left things the way they were and not have my home invaded and disrupted by construction and workers, etc.And I think landlords also forget that tenants aren't really in a position to tell you that they actually hate what you're doing.  

Hey everyone I'm a big fan of the forums and podcast and this question may be a little out of the ordinary but here it is.

I live in the SF Bay Area and have some very loud, dirty and overall disrespectful neighbors ...

I am not suggesting you can do this with any and every tenant, but when you have someone who has paid on time for a substantial amount of time and then something happens to disrupt this, I would say that it is not a good idea to push them away as a first response.   

The easiest way to disrupt or prevent an easement by perscription is by giving consent.

Both may qualify but the obvious choice would be the one lease disrupted by the move and the one you can more completely screen with the lease amount of effort and risk.

Not to mention vacation areas can get hit with any number of devastating disasters like fires, earthquakes, hurricanes, terrorism, flooding, tornadoes, air travel disruption or even just economic disaster.

The only landlords that does not have to worry much about Covid-19 economic disruption is the ones that does not have a mortgage or has enough equity to sell profitably in a market that has slowdown.