Speaking as someone approaching 45, my opinion:
1. You've gotten older which means your tastes have become more nuanced and requiring of depth. Your older mind has a lot more connections that require stimulation in order for you to actually get anything out of your entertainment. As a result, your entertainment has to contain parts that interact in more interesting (sometimes more complex) and dynamical patterns. There has to be more substance and layers to the content you take in such that it gives you something to puzzle through or pontificate upon, again providing stimulation to all those extra connections that have developed in your brain. Seemingly illogical chains of events or sequences are not as easily accepted unless they are able to operate on a deep personally emotional level (i.e. it can't be random teenager chittering and flailing).
2. Your attention span has been shaped, at least in part, by the Internet, which seems to induce a certain ADD-like state. This could also be an induced impatience that has built up, again shaped by the Internet culture. In any case, as a result of significant exposure to Internet culture, one can end up assimilating the rapid, and often whimsical, switching of the Internet's attention from one thing to another.
3. Many video games are designed like a baby's busy-center toy (for those that don't know what I'm talking about http://www.amazon.com/Fisher-Price-Discover-Activity-Center/dp/B0025Y07XE); lot's of knobs, doodads, colorful parts (FPSes probably break from this with the monotonous butt-shit brown color palette), and things that make noise but no real purposeful cohesion or coherency. It's just a random assortment of stuff to keep baby mindlessly occupied (so it's not crying). This wraps back into point 1.
I'm not going to hold these statements as being any sort of "truth", it's only my opinion. So, take them as you will. I will say that, for myself, as I was passing through my thirties, I experienced much the same feelings. After crossing 40, however, a funny thing happened wherein I began to make effort to bring more clarity to my life in deciding and determining what things I like, what things I don't like, what things I place importance upon, what my goals are, and how I wish to shape myself as a person going forward. I began dropping a lot of the baggage that had built up. I began to accept there are games I like, and there are games I don't like. Further, that some games I like, others may not, and some games I don't like, others may like; even more so, it's perfectly okay for it to be that way. These are simply matters of personal preference, and it is a waste of time, energy, and a deletion of personal joy to go on crusades about why other people do or don't like the same things I do or don't like (leave that kind of thing to young 'uns that have yet to learn better). The need for that kind of external self-validation has been vanishing as I have gained more ability to evaluate myself by more own internal metrics, rather than constantly trying to compare myself to everyone else.
I still play video games, though I don't have anywhere near the time I did when I was younger, but I have become much more choosey about what games I play, but I am not beyond experimenting outside my comfort-zone (that is, trying games I don't normally play just to see if I would like them; hell, for a passing time, I even found Destiny interesting, till I discovered the complete absence of plot, story, and depth).
Everything has its season, and when that season is done, you move on. You don't waste your life looking back and trying to live in the past. The past is done and forever frozen in its state for eternity. The present is where we are now, at this very moment and where our energies are spent. The future is the possibility, shaped by our current actions and choices, that we eventually find ourselves in and for which we prepare. Live from the past, live in the present, live for the future.
ADDENDUM: By the way, I've been playing video games since I was about 7, and I'm approaching 45; you do the math.