Here's the thing: this isn't something new. Every movie, comic, new iteration of any media franchise does this, mostly when it changes hands. The Spider man in the Sam Raimi movies is different from the Marc Webb version, Batman's suit was different in ALL those movies.
I'm sure someone will say, "Well, that's not how he looks in the comics." - I hate to tell you this, but it changes a lot there too. Here's a good list (why make one when it already exists) http://screenrant.com/superman-man-of-steel-suit-costume-history-versions/
Costumes change with the times and it's sometimes hard to remember that we, the older people in the audience, aren't always the reason things are made. For every one of us old enough to remember the Christopher Reeve movies I barely made that cut), there are just as many young adults/children out there who are seeing this all for the first time. They are who these movies are made for, they are the ones who will buy the games, the toys, the comics. We might, but I'm going to guess it's a far smaller percentage.