widgets are useless as well, why do i need to look at my facebook status or twitter status on a half shrunk screen while there is already an app on system which does the job properly full screen and i can open it in a few seconds.
Not all widgets are useful, just like not all apps are useful. There are good ones and bad ones. The ones you described are somewhat questionable. I'll give you some examples of what I feel are useful widgets for me.
Sometimes, the amount of info you need is small enough to only need a small portion of your screen. For instance, I have a widget that displays sports scores. It is useful to me because I mark which teams are my favourites and the widget only takes part of the screen to show the score. I can quickly glance at this information without needed to open the app. A weather widget is also useful to me as the little bit of info like current conditions is all I need to see at a glance that only takes a small portion of my screen.
The most useful widgets to me are those that enable me to control certain system settings from my home screen. For instance, to turn auto-rotate on and off, I would normally have to go into the settings and scroll through the list of settings to turn auto-rotate on or off. I have a widget that with a single tap from my home screen, I can toggle it on or off. I have another widget that changes my sound profile from my home screen. With a single tap, I can turn off all notification sounds, while leaving my ringer in low volume and my alarm sound on. I use this when I go to sleep, so I am not disturbed when I get an email, but the alarm will still wake me. When I wake up, I tap the widget again to increase the various sounds to a normal level. When I go out I tap the widget to turn the volumes up higher as I will be in a noisier environment. To do this manually would take many taps of the screen in the settings.
These aspect of Android phones do take some time to configure. I find that being able to configure my phone this way, makes certain functions more convenient for me in the long run.