Could anybody explain me....

...why the PSP has only one analog-stick? Why didnt they add it to the PSPgo? Why wasnt there one in the FIRST PSP??!!
Is Sony just absolut crazy or what can be the idea behind having only one analog stick?
Thats almost as weird as having a huge screen but makin only the half of the screen work oO (nothing to do with an actual product)
or... making a handheld without battery so you have to plug it in all the time oO

There's no good reason why they didn't add another stick in one of the iterations they seem to be shitting out yearly other than they're just really stubborn. It wouldn't break previous games that didn't map the stick. It would only make ports easier. Stupid decision.

Why didnt they add one in the first PSP?

I assume they didn't add one on the Go because it would separate the user base. Some PSP's would have one analogue stick, and some would have two. It could cause issues with devs developing games designed for two analogue sticks, and then just tacking on a really really terrible control scheme for those with the older PSP's.
 
As for why it didn't originally have two, maybe they wanted to encourage original games that are suited to a handheld (e.g. Patapon & Loco Roco) and less crappy ports of console games. Although it turns out that they're still getting mostly crappy ports of console games, just with janky controls too.

" Why didnt they add one in the first PSP? "

" I assume they didn't add one on the Go because it would separate the user base. Some PSP's would have one analogue stick, and some would have two. It could cause issues with devs developing games for two analogue sticks, and then just tacking on a really really terrible control scheme for those with the older PSP's. As for why it didn't originally have two, maybe they wanted to encourage original games that are suited to a handheld (e.g. Patapon & Loco Roco) and less crappy ports of console games. Although it turns out that they're still getting mostly crappy ports of console games, just with janky controls too. "

Stubbornness,  PSP 2 will have 2 sticks and I think even Sony has concluded the current gen PSP/PSP go is a failure.  I always thought about picking one up, but never have just because of this issue.  The lack of nubs and the god awfule "trigger like" R2, L2 has made me question them as of late.  They've been making some god-awful decisions for awhile now, starting with the PS3 price point at launch.  

" @MattyFTM said:

" I assume they didn't add one on the Go because it would separate the user base. Some PSP's would have one analogue stick, and some would have two. It could cause issues with devs developing games for two analogue sticks, and then just tacking on a really really terrible control scheme for those with the older PSP's. As for why it didn't originally have two, maybe they wanted to encourage original games that are suited to a handheld (e.g. Patapon & Loco Roco) and less crappy ports of console games. Although it turns out that they're still getting mostly crappy ports of console games, just with janky controls too. "

PSP Go doesn't play UMDs. Everything in the store would be compatible with the original, everything compatible with Go would be digitally downloaded. If your controls only with with 2 analogue, lucky you, you don't have to make a UMD version. "