That Patch is the issue. The patch is the work either of fans of the game on their free time or the creators of the game who got on on their own and did it either for love of the craft or because they were paid to do so. The way i understand it, every game would have to be patched to work with the new architecture, which is grossly cost-inefficient especially considering companies have to pay console manufacturers for every patch they roll out, or the old architecture has to be emulated universally, which can be imperfect at best considering the way some emulators i was using for the PC couldn't run a select number of SNES games properly.
The cloud allowing for background emulation of titles is probably the smartest choice. The smartest choice for sony is to provide it as they go with no charge for those who have already paid for it on the previous generation, in doing so they open themselves up to tremendous goodwill with the consumer. Crossbones not having a similar service would force it to one of the unwieldy options, which i doubt they're gonna do.