You have to think "total investment". The combo player ends up much cheaper.

If you buy a BluRay/HDDVD combo player you will feel compelled to buy a bunch of high-def disks.

If you buy two game consoles you will feel compelled to buy a bunch of high-def disks AND a bunch of games... and you know how much money THAT's gonna cost you

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8