Yes. Subs!dies Is a Four-Letter Word
There just might be a case in favor of loan guarantees. They can be considered to be regulation insurance. If a government stands to lose money (that might be used to buy votes) if it passes preposterous regulations, it has an incentive not to do so. (If any of my readers can figure out a better way to stop regulations before they start, I'd like to know what it is.)
On the other hand, it is a very bad idea to try defending subsidies in general. Such subsidies will usually either go to the obsolete or to the latest fad.