Only for short term - people are ready to sacrifice themselves in the name of better future. However, if this future never come, people lose their motivation - I saw this effect twice in my country.
Statement
to improve life of workers while trying to make better conditions of they work and reduce amount of their work is false as well?
It seems, that work is needed to survive in any system, either in communistic.
Yes, I guess it's like building a `tree-house` in childhood/teenage. However, it seems never worked in bigger scales, for example, while building a road in length on tens of kilometers or building a hydropower plant.
History of USSR shows that in long terms it didn't work

I'm sorry, but I can't follow you here. I don't understand how this responds to my previous post, or is related to your first post.
No, You didn't get the point. Amount of money, which people actually do earn within capitalistic system, not always shows amount of work they have done. For example, if man buys a real estate and then sells it for a larger price, he has done a small amount of work and made a quite nice sum of money. Although, amount of money made in such `business` does not represent correctly amount of work done.
However, money still is good mean to evaluate amount of work done. For example, 2 workers digg a trench each. One of workers works better and diggs a 10 meters of trench per day. Other one is more lazy, he smokes and takes pauses more often than his buddy, and makes only 5 meters per day. Should they both receive the same pay (or equal access to resources, if there is no money as such)?
Ok, I'm following you here.
In the example, my claim is that the workers don't work as hard as they could because there is no reason to. Capitalism does not provide them with any interest in their labor because they have a weak relationship to their actual activities.
And I don't know whether they should receive equal pay, or access to resources, I would say that this decision would be up to their community - be it a town, an industry, or an organization.
- August
If we have no business with the construction of the future or with organizing it for all time, there can still be no doubt about the task confronting us at present: the ruthless criticism of the existing order, ruthless in that it will shrink neither from its own discoveries, nor from conflict with the powers that be.
- Karl Marx