I'm not sure in what other case it's considered appropriate to lump all the subsidies together in a total just because one person happens to be involved in each. On a case by case basis, each company is fairly large, and possibly not even unusual in the amount of subsidies it gets. Large companies often get lots of subsidies, because they target them, strategically. In this respect, Tesla is no different than GM or Ford, SpaceX is no different than Boeing, and Solar City is no different than General Electric. Each of those non-musk companies were in the top five of total Federal, State and local subsidies recently[1].
Calling out Musk's companies as exceptional in this regard makes for a nice narrative, but isn't necessarily supported by the facts.
1: https://www.washingtonpost.com/blogs/govbeat/wp/2015/03/17/t...