It's a gamble, or should I say calculated risk?

We have not chosen to go there, partially as we have not had any of those types of things yet, but just food for thought.Dan Dietz

Gambling works out fine for some people. 

I also bought 2 acres of raw land in WA state that was a good location on a highway, and gambled on having to get tests done, etc.  

Worth the gamble in my opinion.

He became a devout born-again, ditched all his gambling buddies and started spending all his time in church.

I guess the main reasons I’d want to keep the house are 1) ego - to be able to say “I own a rental property” and 2) hope for things to magically turn around and one day sell for profit (gambling...)What would you do in my shoes?

I see it as a form of gambling. 

It's not just the porosity and sealing issues, well-chosen granite is not nearly as vulnerable to that as some of the trendier lighter more open grained granites that people felt compelled to use by their designers. 

You're gambling for a chance of appreciation with lesser cash flow.