Yea the deal is you need to generate a higher pressure in the Pump than what is in the tire , to raise the PSI in the tire ....

But as said a Floor pump you can use the whole body weight to push down the plunger , but for on the road puncture repairs

the mini-floor pump like Morph pumps are allowing you to push against the ground as well ..


the presta valve is not the issue , (unless you dont unscrew the nut and tap the pin before you start pumping )
(then operator , not the valve's shortcoming)

the air in the hose escapes , the air-pressure in the tire closes the stem check valve , then screw down the nut again..