Leaving long clippings on your grass may encourage thatch.

Adding leaves in not only encourages thatch, it also helps to redisitribute any diseases present on the leaves. and provides great breeding places for certain pests and may encourage molds.

It IS in fact a better strategy to use proper mulching mower blades.

The proper mulching blades leave very short pieces of grass. These are much better able to get broken down, and thus provide the benefits you mention.

Unfortunately there are many misconceptions about lawns and what they provide.

A thick, healthy lawn provides protection from street noise; cooling from the sun and helps prevents soil erosion.

Most people over fertilize, over water and over cut their grass.

My credentials for responding thus are that I am an environmentally responsible, working horticulturist, and have more than 40 years of hands on experience.

Just saying. ;-)