This community's relationship with Intamin is incredibly perplexing to me but I don't feel like getting into that too deeply right now. What I will say is that I know of no other Intamin coaster that has had the level of issues that Pantheon has seemingly had and after my trip last month I am even more convinced that a lot of this is on BGW. Intamin coasters have opening teething issues -- there is no denying that -- but in this case I think the issues and downtime are drastically being magnified by people who are using an issue as an excuse not to work and then having no ambition to actually open the ride when the problem is actually fixed. This is compounded by a park that is CLEARLY short staffed and, on many occasions, has multiple rides down in which a small group of mechanics are trying to repair everything at the same time and, more than likely, aren't even being thorough when they are working on an issue.
To your point though, you aren't wrong.... but these are things that BGW needs to resolve -- especially in the way they handle situations. If you put various other coasters in place of Pantheon there is a good chance the outcome would be nearly the same.
And RMC? It's unreal that you are using Twisted Timbers as a poster child for reliable openings while both it, and SteVe, were absolute disasters in the beginning.