They are just copying IPL. One of the most exciting part of IPL is a team can play at most 4 international players in a team. Which gives it an international feel. It makes it popular in the countries of the players participating as well becomes more thrilling to local users.
The exciting part of IPL according to me is the level of competition and the quality of players and they should increase the number of foreign players in a team for the real excitement but they have their restrictions and we assume that they are doing that to help the domestic players and it is a good thing as it is giving them a financial boost as well.
You cannot call other tournaments copying IPL, club matches are not a new concept and Soccer is more popular in the club circuit than International matches other than World Cup and Cricket is just trying to replicate that in the T20 format.
If they increase the number of foreign player in a team, then what is will be the benefit of holding a T-20 competition?
The primary goal is to find aggressive all rounders and to earn money for BCCI. In my opinion it is okay to have only 4 foreign players and put an age cap to avoid the oldies. There are many young foreign talents who are not getting an opportunity here because IPL allows franchises to buy old or retired players.
I think they should also do the same for Indians as most veterans are now playing as if it is a domestic cricket.
I think the decision to have 4 foreign players in the squad is the perfect decision. Because the main goal of BCCI is to find talented young players. And after every IPL we can see BCCI has got a lot of young talented players. As a result, the idian squad is always strong. I agree with you, older players should be avoided. And young players should be given more opportunities. Because the youngsters will lead the next Indian team.