It's worth it when the lands are of the aesthetic value we are looking for and/or adjacent to my own holdings in different parts of the painted desert. 

While I prefer the aesthetics of Lamborghini I must admit Ferrari does an important thing much better.

Not only does it give me a competitive advantage because not everyone else has good windows and EVERYONE knows how awful bad windows can be (no locks, torn screens, poor aesthetics, etc.) but it saves on my utility bill as well. 

My philosophy is  - who am I to enforce my own aesthetic values on the folks who are intimately involved in the day-to-day use of the property?  

Aesthetically speaking, nothing looks uglier to him then a pipe sticking up in the middle of a bunch of sleek panels.

Aesthetics.  

Aesthetic work throughout but full kitchen and master bath gut.

Maybe it is aesthetic and family friends like to purchase the oleander from them?

It will buy some goodwill (if you even want to retain this tenant), give you some control over the aesthetics, and it will cost you a lot less than the time it takes to argue with him and write this post does. 

But I've always managed to find insurers.You can cover it with vinyl, but if you have a property with nice bones (say a nice, or even a middle class old Victorian) putting vinyl over it may throw off proportions of any attractive molding the building may have.If it's a property on Munjoy Hill/West End of Portland, you may want to consider remediation, as it would likely pay off in increased value/aesthetics/resale.