How can Sony and HTC expect high sales when availability is poor ?

Galaxy S5 already launched and now on sale in my country.

Where are HTC M8 and Xperia Z2 ? Where is global roll-out ? Anyone who walks into a store will have 2 familiar options , 5S and S5 abundantly advertised and available on wide range of stores/carriers/online.

Why would any consumer would wait for some unknown device/less brand value device when Galaxy or iPhone are available right away ?

For example , A guy wants a printer which works over Wifi , he would go to a store , Sales guy will say "We sell HP and Wipro printers..........Wipro printer is not available but HP printer is available"

Guess which one would people pick ? Yep that's right.People would generally pick a more familiar brand but what if less-familiar brand is not even available ? Choice is 100% more easy than before.

Imagine , reverse situation where HP printer is not available but Wipro printer is available , Atleast consumer will look into this brand instead of ignoring it.

Imagine same with a smartphone and keep average consumer in mind.

I think marketing is one good factor but availability plays a major role too imo.