I'd hate to be the bearer of bad news, but if Red Dead Redemption, and which did not come out for the PC, taught us anything, it's that Rockstar has no trust at all with the PC community as it pertains pirating.
I believe that Rockstar is using the same engine for GTA5, too. This is going to be a closed platform PC (i.e a console) exclusive.
All the hours spent on GTA IV on PC flying around the city as Iron Man, riding up buildings as Ghost Rider on a flaming motorcylce, and all the amounts of craziness and choas will love to disagree with you.
RDR didn't come to PC because it would not have been profitable enough to port a basically brand new IP that has no real following on the PC. Plus, there were rumors that the coding for RDR was just a hodgepodge mess and basically "duct taped" together, so porting it would have been a pain on a technical level, too.
Every major GTA has been released for PC including all of the pre and post III era ones. In fact, the original GTA launched on PC first way back in the late 90's.
Rest assured, GTAV WILL arrive for PC at some point. My guess would be 6-9 months after the console releases. I, myself, will be double dipping by first picking up the PS3 version and then the PC version down the line because I believe its the only definitive version thanks to upgraded visuals and most likely strong modding community.
If you're really concerned for the PC version, why not sign this petition at Change.org to bring GTAV to the PC. (http://www.change.org/en-CA/petitions/rockstar-release-gta-v-on-pc) It's already going very strong at 170k signatures.
I wouldn't jump the gun and say a next-gen port of GTAV automatically means no PC release. The PS4 is basically running PC architecture (x86) this time around. Thus, even if a next-gen port gets in the way of a PC release, it wouldn't take moving heaven and earth to port it to the PC.
The PC may be considered "cumbersome" to certain people, but those people probably wouldn't bother buying/building a gaming PC regardless and would stick with consoles. Besides, what you mention is irrelevant. Steam takes about as much effort to install as an Android app. Windows Live was a mistake on Rockstar's part for GTAIV, which is why LA Noire on PC was released on PC with Steamworks.
Max Payne is the most Recent Rockstar game to be released and that came to PC that as well as the fact that every GTA released aside from the portable titles has been released on PC. Usually Rockstar takes extra time when getting their titles to PC since it requires extra work to bring a game developed for consoles to PC. It will come to PC but at a later date since right now they are focused on the console release. Once the console version is out they can focus on the PC version.
I'd be afraid if this came to PC, it would have like 3 layers of DRM. And than the game wouldnt boot lols. These new games are becoming annoyances with PCs especially, not consoles, since consoles are already tailored to their specs unlike pc.