I wouldn’t exactly say it is easier, in fact as far as I can tell the hitboxes are fixed compared to 1.6, whereas there you hit in the head and it registers a arm shot because of the way gun is held, in source you hit them in the upper chest and you are most likely going to get an arm shot if they are burst firing or tapping,if they are full on spraying it is a lot easier as their rifles drop and chest opens up. Plus with the latest patch, registration on hits works *edited*ing amazing. I haven’t seen unregistered shots in days, even on 90 ping dsl.
As for easy shooting, kinda, kinda not, watch some of the pros, the way they shoot shows that running and gunning can be deceptive at first. There is a lot of room for improvement and really doesnt effect game dynamics because it is just as easy by that same measure for the other dude to kill you.
Granting that shooting is a tad easier, the maps are a lot more complex imo. Contra for instance, probably the most tactically complex map in source. You gotta use your head more than your hands.