Why do we only work in gas stations or restaurants? Why no Nepali guys as carpenters/plumbers/cement/painters/ etc? In America, I mean.

They do. Don't assume anything.

cashiers and waiters are unskilled jobs whereas the other ones are semi skilled to skilled jobs, thats why

Agree with kaji sab

Exactly, Nepalis don't have any skills. That's why we bring immigrants from South America to build our houses in Kathmandu.

I know at least 4-5 Nepalis who work on construction business, why are we even having this discussion?

BTW guys, those who are working in constructions, they make quite a good amount of money compared to the cashiers or waiters. I have seen guys make really big bucks in those jobs.

This is my reason why there is less. However we are learning its potential and more Nepali are getting into. It is a skill that we don't foster back in Nepal. I mean I have seen plenty of Ph D candidate who have never used a drill in their life. We grow up not even using a simple tool. A new Nepali will have no clue about anything in a Home Depot. We expect our kids to be engineer and doctors but carpenter, plumber are not the proudest job that our parents are willing to brag about. But things are changing and more will join this profession. I have seen construction worker and few mechanics but not whole lot of carpenter and plumbers. It will take time.

its good idea. I no some guys who bid jobs and make 50-100 dollars an HOUR, if they are the contractor, in USA construction.

I completely agree with Vhotee. Back in Nepal, we are used to getting things done for us. If a tap leaks, we call some to fix it. If we need to hang a mirror on the wall, we call some to drill the hole for us. So we never get to do anything by ourselves and do not learn how to use any tools.
Two years ago, I built my house working with a brick layer and 2 other guys. It was very daunting in the beginning but slowly I learned the trick. If you have good tools, some patience, you can learn the skill. So invest in some good tools; you will always need them. My house is worth $380,000 and I got it done at $235,000. I saved more than $100,000 by building it myself.
I have an american friend who quit his desk job. He now builds houses and then sells them back. It takes you 6-8 months to build a house and when you sell it back, you make a profit of close to $100,000. You save a lot of money by building your own house. You only pay for the materials. But you should be ready to work under rain, and do some physical work. But personally, I loved it.

Doesn't every engineer have to take one workshop class where they have to learn about everything from carpentry, electricity, smith job etc and actually have to do the jobs ? Or it varies by colleges ?

Here is some answer:

http://sajha.com/sajha/html/index.cfm?threadid=110021&noofposts=1

And one other reason, may be this has to do with our history and culture. We nepalese have never been builders. We haven't undertaken any engineering feat in our history.

Have you seen the physical fitness of the Nepali men compare to other men, like Hispanic, black, whites.

talking about feat of engineering; Mount Everest nai nature/god le banai deko chha tehi bhayera pahiley dekhi nai alchhi baani hami nepali ko.

nepali peoples definition of work bhaneko kurshi ma basera kalam le sign garney kaam matra kaam ho.

नेपालमा काम गर्न लाज हुन्छ : बिदेशमा गएर काम गर्छन् : सुन्नु भएन २०२२ मा हुने विश्व फूटबल को तयार कटारमा हुँदैन्छ र त्यहाको स्टेडियम बनाउने क्रममा कती नेपाली मरे ? ति मर्ने हरु सबै Construstion काम्दार थिए ?
हाम्रा पण्डित हरुले ( पहिले पहिले धेरै जान्ने सुन्ने पढेलेखेको, लाई पन्डित भनिन्थ्यो, हाम्रोमा एउटा दुईटा कोही पन्डित थिए होलान तिनका सन्तान सबै पण्डित गनिए , पछी पन्डित शब्दले छुद्र बाचक् को रुपमा लियो , सम्झिनेले सम्झिए ) आफुलाई उपल्लो स्तरमा राख्न काम अनुसार जात भात को श्रीजना गरे |

यसरी श्रीजना भयो हाम्रो काम गर्ने शैली ! काम्ले सानो र ठुलो हुने भए पछी को सानो हुने ? यो साझा छिर्ने र ठुला ठुला गफ हाक्ने हरु तरकारी किन्न जादा स्पोर्टस झोला लिएर जाने अनी देख्नेले ए जिम गएर  आएको भनी सोधुन नकी तरकारी किनेर आएको नभन्ने कती छन | अर्को कुरा हाम्रो शिक्षा प्रणालिमा पनि केही दोश छ , शिक्षाले ज्ञान दिनु पर्ने तर अहम थपी दिन्छ |

मैले पनि पण्डित्याइ देखाइ दिए | एस्तै मात्र गुण छन हामी नेपालीको |