Insomniac Games from what I remember were never first-party developers like Naughty Dog, Santa Monica Studio, Nintendo's developers, and I believe 343 Industries. Those developers are owned by Sony, Nintendo, and Microsoft. That, or they're under a contract like certain voice actors such as James Arnold Taylor which is a reason why you don't get to see or hear great things in other places. Some day, we'll get JAT in an anime or something else than Disney stuff, cartoons, and some games. Insomniac Games is like Bungie and Ninja Theory where they have certain franchises they can make but don't own the rights to it. Ratchet & Clank is a Sony product just as Heavenly Sword is, and Halo is owned by Microsoft. It's not like Nintendo making Mario games and owning the rights to the Mario franchise; if they didn't, it'd be really stupid. Or Sony owning the rights to Uncharted and having a Sony company: Naughty Dog, make the game.
Insomniac Games, like some developers, just has a couple franchises owned by a company. Spyro was owned by multiple companies, the current one being Activision and they kind of don't know what to do with it. Insomniac Games only made 3 Spyro games, though and they were on the PSOne, the console to be on back then. Ratchet & Clank and Resistance are owned by Sony, so those two are locked to Sony systems as long as Sony owns the rights. Fuse (formerly Overstrike) is owned by EA, so if there's ever a sequel, then expect the game to be multiplatform. And now, Sunset Overdrive is owned by Microsoft Studios, so it's locked to Microsoft systems.
That said, Insomniac Games have the most control when it comes to R&C games and maybe Resistance, I'm not so sure, but I remember Insomniac Games' first game being a first-person shooter and that was Disruptor from 1996, so while they make great platformers, puzzles - you have to admit, some of the puzzles in A Crack in Time are difficult -, third-person shooters, and adventure games, they don't have enough experience with first-person shooters or the record of good FPS games. Resistance I heard was an interesting concept and the controls just needed tweaking. Resistance 2 just became another generic FPS and the third game was closer to the first, but still had the whole another FPS rather than something unique like the first game, Borderlands, Mirror's Edge, and Portal. Sunset Overdrive looks like something unique despite it still playing with zombies, an overused idea. Also, it looks like Microsoft might not interfere with them at all. There were rumors that EA interfered with Fuse, but I still believe Insomniac Games released the concept too early and I find them to be one of the more respectable and humble developers out there. Fuse, All 4 One, and Full Frontal Assault all had decent to negative reviews and they took it as something to learn from rather than complaining that people don't understand their genius. That's cool in my book.
Anyway, I just don't really understand when people complain about developers staying first-party or going multiplatform. So they made a couple games on one system more than any other system if at all, that doesn't mean they're a first-party developer. Unless it's specifically stated that such company is owned by another company, than there is not reason to believe that they cannot bring games to other systems. Square Enix with Final Fantasy XIII, probably Final Fantasy XV and Kingdom Hearts III, Kojima Productions with Metal Gear Solid V and Metal Gear Solid 4 for an Xbox 360 port, and now Insomniac Games with Fuse and Sunset Overdrive have all gotten backlash for going multiplatform since they were supposed to be first-party developers or that the other system will weaken the potential of the other games - might have been true back then, but the PS4 and Xbox One are so close that future games are probably going to perform almost equally. One, Square Enix has developers making games for almost every platform out there. Two, Metal Gear began on MSX and NES, so Kojima Productions has been making Metal Gears on Nintendo and Sony systems a long time ago. And three, never once was it stated that Insomniac Games is owned by Sony. I know that Square Enix and Insomniac Games have been making controversial decisions with their recent games, but for one, Square Enix has multiple divisions and Final Fantasy is not their only franchise, you have Dragon Quest, Bravely Default, Sleeping Dogs, Deus Ex, Hitman, Tomb Raider, and plenty more; Insomniac Games just entered the field of multiplatform games and they're going back to being an underdog and All 4 One and Full Frontal Assault were more like experiments rather than actual Ratchet & Clank games. As for Kojima Productions, just look at Zone of Enders and fans' desire for another ZoE or the recent issues with Quiet.
Then there's the opposite. Where people make ridiculous requests for Halo on PS3, Uncharted on Xbox 360, The Legend of Zelda on PC, or something stupid when it's clear that it's not legally possible unless the rights owner allows it and they'll never allow it since it's something to attract customers. Want to play inFAMOUS? Get a PS3 or PS4. Want to play Ryse: Son of Rome? Get an Xbox One. Want to play The Legend of Zelda? Get a 3DS, Wii, and/or Wii U. Businesses are out there to make money; they're not running a charity. Hell, charities are out there to make money too, but to direct that money to certain causes - hopefully causes such as cancer research and not Chevrolet Corvette Stingray "research".
