When it comes to down to games and shit that really just boils down to personal preference really. You're right that people generally don't keep an open mind and that's frustrating but luckily it's easy to spot these kinds of people and avoid debating with them. A lot of people, like your in-law, will form a quick opinion about something and not think twice ever because it's really something that's not important to them. I'm the same way with smartphones - I think they're the biggest fucking waste of money because the internet is so ubiquitous in my life that it's relaxing to me to be able to step out of the house with my phone and not having the means to satisfy my urge to check my e-mail, indyDDR, Facebook, etc. In my opinion, phones are meant for simply talking and texting, I don't need any bells and whistles and I certainly don't need a data plan.This always happens with videogames. I know a lot about most games and trying to defend the game industry or trying to prove why something is good or bad to fanboys is impossible because they have these ingrained thoughts and haven't opened up their mind to other ideas. Trying to tell my mother in law that games are more than bleeps, bloops and pixels made for spastic 11 year olds is impossible. Trying to convince my friends that PS3 isn't the best system is nearly equally impossible.
You bring up a good ol' can of worms argument with your point about the PS3. This is something I believe we can debate and reflect on regarding the industry as a whole. I feel like there is a lot of homogeneity in this generation where effectively the two big systems are the same. In other generations there was a clear "winner" (NES, SNES, PS1, PS2) but it's really hard to define who is going to come out on top before the next line of consoles come out.
On paper the PS3 is a better system, that I can agree with. Blu-Ray is better than HD-DVD, the interface is better, their multiplayer service is free, and the controller is better. However in execution the PS3 has been a huge fuck up. The Playstation Network is awful, framerate drops are rampant, and all the hullabaloo about the PSN getting taken down and the prosecution of the hacker who cracked PS3's encryption have all been terrible PR for the console and for Sony.
Xbox has had it's fair share of disaster too. Red Ring of Death, anyone?
Game quality at this point doesn't even matter since both the Xbox and PS3 have nearly the same library. Game companies can't afford to pigeonhole their product into an exclusive sector of the market anymore - they need to make their investors happy. With production costs being what they are you see a lot of games trying to appeal to the lowest common denominator. Games are easier, shorter, developed for both systems, and sequel-ized to hell (and more often than not these sequels use the same engine, character models, and art created for the original). Or better yet, you have companies that pull slimy shit like selling you half a game and then making you buy the rest through DLC.
If we have to depend on independent developers for innovation and creativity and there's something incredibly fucked up with the industry.