For now , it is close to impossible for someone to hit 7/7 and by making it to 4 league like you suggested then they are basically increasing the chance for people to win. This is a free challenge and it bring nothing more than extra traffic to them, all those extra traffic isnt really guaranteed to bring in profit to their site as well
Plus with making it into 4 leagues instead of 1 , that means extra work for them to setup the whole thing in their system. As of now, the majestic 7 is still kinda broken there and some people including me hasnt been able to make some picks. Imagine adding 3 more
Well, what I was suggesting would drop the reward, it is quite difficult to hit 7/7 as you said, so in this system they are giving gamblers a chance with 4 leagues which is not nice for the casino but they are also dropping the reward to 0.25 so they are actually spreading the loss instead, after all someone eventually could hit 7/7 one day and they would have to pay up 1 bitcoin full, but with my idea it is 0.25 instead.
Obviously there is no clear winner here, gamblers get 4 chances which is good but gets 0.25 instead of 1, casino pays only 0.25 instead of 1 but also has 4 places people might hit, it is not better for anyone not worse for anyone. The other broken parts thing is all about fortunejack, they could just hire a good developer to fix things if they want to, obviously do not want to spend too much manhour on something free I suppose.