Catalan is the most solid opening choice for white for club and tournament players. I believe it is more strategical and not theory heavy therefore making it a logical choice for players who doesn't have much time studying the latest trend and analysis on recent theory.

The main difference between 7. Ne5 to 7. Qc2 is that it gives black some limited responses if he would like more than equality out of the opening. First, black cannot reply with ... b5 since this will expose 'Ra8' to 'Bg2'. Secondly, white can easily find squares and play for his pieces. While black slightly struggles to untangle his queenside. 

Let's go back with the main move of our discussion: 7. Ne5

If you'd like to read more information about this opening please check the links below:

Chess.com's FIDE Master Kostya Kavutskiy Opening Review
https://www.youtube.com/watch?v=A0GBJn5Ro54

Wiki's Introduction About the Opening 
https://en.wikipedia.org/wiki/Catalan_Opening

Kramnik plays the Catalan
http://www.chessgames.com/perl/chesscollection?cid=1010935

nice

Yes nice information, but can see immediately that the claim for low theory is not true. Also white doesn't get very far without considerable positional ability. For example in the main diagram if reach an endgame white will need to be able to convert an opposite colour bishop endgame. Think the skill gap between GM, like Kramnik, and club players works mostly in blacks favour in open catalan, i.e lines with d5xc4.

Your analysis is okay as a starting point but I'd point out that theory goes much deeper than this

Post #5: Except 11...Bb7 has never been played by a Super GM in that position with black. 

Chess opening books not very fashionable at least on chess com but it is remarkable how much better  the analysis is in Kotronias's  "Beating the flank openings". This was published over twenty years ago. dpnorman is on the right track but for example after 18Qf2 Nd5 19Re1 considers 19...Nb4etc, goes past 19be3 nd5 several moves, also considers 19be3 bxe2. Can't be bothered type out all the moves. In fact considers whole line with 11...e5 very drawish, and recommends 11...a5 as more ambitous.

Only played  one or two games with catalan as black back in '96. Wish stuck with it as classical openings suit me quite well, and didn't realise what a good book Kotronias's was at the time. 

Know next to nothing on 5...a6, but it seems black will get good compensation for peice in final position. So white needs to look for improvements somewhere earlier. The catalan can get more complicated than the OP seems to think. White can get an easy game with 5Qa4ch bd7 6Qxc4 but don't think has any advantage.