I think its a silly arguement that old games are better, or that the huge wave of movie/tv tie-ins and sequals are a new thing. There were just as many shit games then as there is now; maybe we're just more forgiving of the flaws of older games, letting our nostlagia gloss over the bad points. Games getting shorter? Since I only really play RPGs all games are long to me so I can't comment on that, but a lot of good retro games are arcade ports, designed for quick play. We just played them more 
Going back and replaying many of the older PC games circa 1995-2000 in the past few months I've concluded that it isn't nostlagia that makes them seem better, at least for me. They are still considerably more fun than anything new. Also, they all worked out of the box for the most part. I never remember having to patch games for singleplayer on PC until after 2000. These days it seems I have to download patch after patch to get anything semiworking.
Particular strong examples being C&C Tiberian Dawn and Red Alert. No new games seem to have as interesting stories or engaging gameplay as the above in my opinion. And in the case of C&C, no games come anywhere near consuming so much time of my life. C&C TD/RA alone seem to make up the majority of my childhood and early teen memories.
However, I agree there was always lots of shitty games. I just never played them and stuck to the quality titles that interested me. But these days the so called quality titles don't seem to be particularly high quality. Just look at all the crap that seems to get 8 and 9s in the reviews these days. Infact it seems almost all new games score that high despite their quality.
