If you are actually asking a serious question: while a patron is primarily motivated by whatever catches his interest, a corporate conglomerate funding the same investments is motivated by profit. They would have more of a motive to select the kind of investments that will succeed and pay for themselves, allowing for a more economically efficient allocation of resources.
Of course, the kind of investments that might succeed and pay for themselves may not necessarily be the kind that is most beneficial to the public at large - but the same applies to the patron.
As you say, conglomerates being profit motivated tend to produce largely uninteresting slop. See the vast majority of the movie industry.
Patrons will produce some very interesting and detailed work but it will not necessarily align with your tastes and there will probably not be all that much of it. European history makes this clear enough (imo).
A system in which individual or very small groups of creators are able to produce work of their own choice that appeals to a small to moderately sized niche of their choosing seems like it should produce the best outcome from the perspective of the typical individual. Fiction books are a decent example of this. We get lots of at least decent quality work because a single author can feasibly produce something "on credit" and recoup the costs after the fact.
How is that any different from hoping that a corporate conglomerate happens to fund something i also enjoy?