I understand it's more boring with hidden other parks, but I also understand the motivation.
If other parks are visible, a competitive player would be motivated to play as slowly as possible to make sure they have a chance to scout the opposing decks (otherwise if you finish your map first, you will not see their decks). Everyone would hate this.
The alternative would be letting everyone view last match's logs which is also not desirable (a lot of work for not much payoff, plus I don't believe scouting other parks is intended, plus it's not even feasible in real life unless you are rushing over to someone else's seat).