Lots of misinformation out there, so...
One...more...time:
The $187 million figure is an estimate from the most recent study commissioned by the County. They re-evaluate every couple of years. 2 D-Back Reps and 2 County Reps sit on the steering committee for the study. The County asked the D-Backs if they wanted to take on a few of the more immediate items on the list and the team asked for those to be put off a year. (So the fund balance won't be taking a hit this year).
The $187 million is not set in stone. It is based on what "could" happen based on the standard useful life of different components of the building and some "worst-case" scenarios like the roof breaking. But this number will be fluid in reality.
For example, an A/C chiller could break sooner than expected and require replacement that makes it likely that it will need to be replaced a second time before 12 years is up. Or if could outlive its useful life and not need replacement at all. Another is if they need to repaint bathrooms once or twice before the end of the year. Replacing panels on the scoreboard is another item. Do they need replaced now? No. They just assume that will need to occur sometime before the lease is up.
It has nothing to do with removing seats. That is not part of the $187 million.
As for the county being broke, this is somewhat true, in that it does not have $187 million on hand to pay for these renovations today. But they don't need it all today.
The D-Backs $4 million in rent goes straight into a fund to pay for the County renovations. Plus the District gets another $700,000 per year from other events to deposit into this fund. So over the next 12 years, the fund will be bolstered by nearly $60 million to make repairs. I believe that fund currently has about $8 million in it (but I am not sure).
Does that fall well below the $187 million cited in the report? It sure does. But that $187 million is not a real number. It is an estimate. And even Derek Hall has gone on record saying it may be inflated, that they may only end up needing a fraction of that amount in reality.
And $68 million might be enough. For comparison sake, the first 18 years of the stadium only required $42 million in repairs to come out of this fund and $10 million of that was for a new scoreboard alone.
The D-Backs are mad because they pay high rent AND they pay for routine maintenance for things such as the field, fan amenities, custodial work, and lighting. They feel like they are getting hit twice because their rent ultimately goes to the fund for major repairs as well.
So what? If I am renting a house and required to maintain the lawn; AND the landlord uses my rent money from that month to pay to repair the A/C unit that breaks down in July, do I really care if I feel like that was "my" money first?
Bottom line is that this is the contract the D-Backs agreed to when the County had to pony up the dough to help build the stadium in the first place. Ultimately, they don't have much legal recourse at this time and they know it. This was all about getting the dispute out into the court of public opinion to place pressure on the County to negotiate a better lease. But it appears they miscalculated terribly.
Derrick saw how that Atlanta stadium is coming out and wants some new toys. lol. All us men really are the same when you get right down to it. 
