Do you think reviewers generally lower scores for games than previous years.

[Reasonable]

RolStoppable said:
This happens pretty much every generation. The main reason is that early on in a generation graphics and technological aspects in general are perceived as more impressive (the jump from the last generation is still fresh in people's minds) and games score a few extra points due to that. The same wow-factor isn't really present anymore later on in any given generation, so scores go down across the board. Another reason is the lack of originality, new IPs are more common in the first half of a generation while the latter half is dominated by sequels which also means that there is less of a positive surprise factor involved.

Or in other words, at the start of every new generation style can garner games quite a few extra points on the review scale while later on more and more games are rated mostly/purely on their substance.

Bingo.  Another factor is around now in a gen the reviewers and their readers start to acknowledge the "extra points" early titles got and how the scores are starting to look a little suspect now and you see more and more reviewers being a little harsher and aiming to look less "starry eyed" in their reviews for big titles.

TBH my advice is never, ever look at the scores.  The scores are meaningless and a horribly coarse attempt to simplify a detailed opionion down to something "bite sized".  If you are at all interested in reviews read the words, gaugue their truth, look for consistent good/bad references across multiple reviews and judge based on those.

Even better, trust your own taste/opionions based on previews, demos and knowledge of gameplay preferences.