Why Don't All Dc Groups Just Release One Session Dc Gamez?

My Cdrw is a memorex 2x2x6 and yes its old and junkie but does the job .. but noticed that alot of the dc gamez released <ISO's> are 2 sessions which my cdrw doesn't support. Like On Cannon Spike i can't burn but Virtua Tennis Released By Nbc which is self boot is only One Session. So u can release Self Boot gamez that are One Session , why don't all groups do that .. Whats so special about Two Session? which not all ppl have & the groups have to know that.