As always, I thank all of you for the incredible input you've given me. I've read through every response and internalized many of the principles that you all have spoken about.
Just to clarify a few things:
The property is in Bakersfield, I live in L.A., so there is no rent control to worry about in this case. The tenants do pay rent on time (sometimes they even pay early) and they do take care of the property (last I checked, I need to stop by again). I don't believe any of the repairs that were/are needed are due to the tenants breaking things, my repairmen would have told me if they had thought foul play was the reason the repairs were needed.
I had a discussion with them yesterday and told them that based off their never-ending stream of request for repairs (some with are trivial), that clearly they are unhappy with the home, with the individuals making the repairs, and the quality of the repair work being done and that they are welcome to opt out of the lease at any time. They then assured me that they love the home, the neighbors, and neighborhood, and that they didn't mean to come across as being so bothersome. We talked about a few more things so I'll wait and see if the conversation changes anything.
At this point the entire house is virtually new: entire sprinkler system is new, the electrical system has been completely gone over, the A/C and heater is serviced, from the remodeling by the previous owner all the cabinetry throughout the house is new, stone flooring, paint inside and out, never had any issues with plumbing, roofing, etc.