1) It is a good concept presented badly. The makers aren't creative enough to come up with new stories. Therefore, they stick to one story for many episodes. They stretch the same story unnecessarily long to increase the number of episodes. There is a very less progress in story in each epsiodes which makes it boring after a while.
2)I personally hate the character of Kunti. She is greedy, grumpy, selfish, rude, good-for-nothing, ungrateful irritating character. (In the initial episodes) She insults the girls and their parents who comes to see Kanaiya just because the girl did not have all those 5 qualities. She herself possess not a single quality, neither her son has any special quality. Still she has greed to get 5 qualities bahu. Actually watching the series further it feels like, more than the son, she wants the 5 qualities bahu for herself. Because she don't move a single limb ever. (Have you ever saw Kunti doing any household work, ever? She can't even get a glass of water for herself.) She just wants the bahus to do all work and give her comfort as if she is in some spa resort and all bahus behave as if they are slave roaming around Kunti to fulfill her needs. Moreover, Kunti is controlling and rules everyone, specially her son. She always keep a point to keep her son all for herself. (If Kunti wanted to keep the control of her son to herself then why did she want him to get married at the first place..?) In short, Kunti wanted maids who can handle her house for free. She is no good than Pratap. She ain't got any right to call Pratap a useless fellow. In fact, she is the most useless person of the house. She is the worst example of mother-in-law. She is the trouble maker and she don't learn from her mistakes. She rather behave as if she got suffered due to problem she created. Apart from gossiping with Sarla, shouting on bahus, telling bad things to Pratap, eatting bhutta, drinking tea, eatting food and having desires for good things (without even deserving it) she don't do any work, ever.!!!
Worst worst worst character I ever came across protraited on television. (I can write a whole book on how much I hate the character of Kunti). I hope no mother-in-law ever get influence (or behave) like Kunti.
3) Jokes are funny if you hear them for the first time. They sound less funny if you hear the same jokes again and again. Same way, repeating same dialogues get boring and after a while irritating. Look like makers don't pay your script writer properly.
4) What's wrong with Prathana's dialogue? Its okay to speak pure Hindi. But why her dialogues sounds like dictionary. In order to speak one simple word, she describes the word in different ways . For example, if she wants to say mother, she could say 'Ma' or 'Mata' or 'Mataji', instead she will say something like "janamdaata...palanhaar..pujaniye..jannani...mataji". Why she needs to describe every word and make it sound longer. Pure Hindi don't needs to be soo descriptive in every word.
4) Why can't other characters understand a single word of Prathana's language? I mean she almost speaks same sort of words everytime and they aren't so difficult to understand. Its okay if someone can't understand few words out of her dailogues but its unbelievable to act as if you can't understand a single word from what she says. If the makers are showing a family living in Meerut (Hindi speaking city), then they should at least understand some of the words of Prathana. (To be honest, I can understand almost everything what Prathana says. Its dumb to show that other character can't understand her at all).
5) Why did Kanaiya got married to 5 girls if he didn't want to stay with them like a husband? He has his own bedroom, the bahus have their own seperate bedroom. They stay separately in their own rooms. If he wanted to stay in a hostel setup then what was the need to doing marriage, namesake! It makes clear that either the Kanaiya character is not into women, or they really wanted free goodlooking maids and not bahus.