Trying to see things from an indie game developer's standpoint, would vote on consoles.
Construct's main objective? To create games. And the most widespread gaming machines are consoles and PCs, I would think. Gaining market share on more gaming platform would be marvellous. Should perhaps see the statistics about consoles and PCs owned/sold.
Other OS-es (mac, linux) :
-are not specially for gaming.
-with current Win support PC area is already covered mainly.
Why to bother more about PCs any more?
Internet:
-the phuture it is, maybe when TV sets will be capable of sufring the net, then this would be a very good target for construct, would think.
mobile devices, android, ipods etc. :
-are again not specifically for playing games.
Consoles remain the target, as being popular, specifically gaming platforms.