You are of course welcome to use whatever you want, as long as you comply with the license. In the case of ProxySQL, that's the GPL. Percona appears to be one person, one René Cannaò, and it looks like he's interested in selling his consulting services. If you are actually making money from using his product, please consider throwing some work his way.
Like I said, Open Source developers should not have to wear hair shirts while their users, sometimes the most profitable companies on Wall Street, rake in the dough.
You may not believe it's a desert due to irrigation.
The central valley survives on water inputs from outside and can't sustain itself on the available water. That's a desert. Much of the land has subsided by 10 feet or more as ground water has been drawn out, and municipalities are commonly drilling 1000-foot-deep wells to have a hope of their being reliable.
Actually, they didn't start with desert. It was marshland before it was farmed. The largest fresh water lake south of the Great Lakes was in the central valley of Californa. It was sucked dry. The entire central valley was made a desert by the hand of man.
The folks who live in the North don't want to have our rivers run dry and to be in unending drought because our water is going to Southern California, where they have made a lot of desert from what was historically marshland, and having made it a desert continue to try to farm it.
The government folks also had the design drawings and specifications. The main thing you get from a visual inspection is an answer to these two questions: Is it built as specified? Are there material failures?
We will probably eventually find out why it was inadequate. Today, we know it was inadequate but we don't know if it was underdesigned or if it was not built as specified.
Money isn't everything -- but it's a long way ahead of what comes next. -- Sir Edmond Stockdale