I find that the deletion of posts that don't add anything to the conversation, like the +1, me too!, etc. makes the quality of content much better since you don't have to weed through a bunch of spam to get to the real content.
The contacting with a message of why there were deleted has been discussed many times, and will be discussed well into the future. There are relatively few mods on this board compared to the number of users. To send a message for ever deleted post would put an unnecessary burden on the mods who are more than happy to discuss reasons for deletion if you'd like to PM them, but would rather not have to justify every post they delete.
If you're finding what you perceive to be an unfair number of your posts being deleted, PMing a mod will get you more answers than starting a public thread.