You obviously have very strong likes and dislikes about various things in your kitchen, which is great to hear, but I don't. You have to accept that others, including myself, may have different ways of doing the same things and getting just as good results.
I" don't see any need to put dry coriander powder in the potato mixture. "
I love coriander powder in the paratha fillings, though not in huge amounts. It gives a lovely flavour. I don't know what you mean by "coriander powder is put only in dry vegetables". Most curry masalas (gravies), whether for vegetarian dishes or non-vegetarian ones, have coriander powder in them.
"...infact the ajwain too can be added in the mixture instead of the dough."
As for ajwain, most Uttar Pradesh families of my acquaintance add ajwain (carom) to paratha dough and sometimes poori dough. It give it a wonderful flavour. It is not the same when added to the vegetable mix, though still quite nice. Ajwain is often added to even plain paratha (and Poori) dough, where there is no filling, especially when parathas are made for breakfast/packed lunch/dinner etc.
"...roasted jeera powder and garlic powder will add to the flavour"
Yes, roasted jeera powder will be good. Most of my Indian family and acquaintances do not like garlic in their food, paratha included. It is not traditionally added to the aloo paratha filling, but if one likes it, why not indeed! I am sure it will taste great, though I personally don't.
"...and the ginger tastes best if it is grated...so that some fine pieces come into the mouth". Many people do not like 'bits' of ginger in their mouth, my husband included. It is absolutely fine if you prefer to grate ginger and chop onions etc, but in a modern kitchen, chopping onion, ginger, green chillies, even coriander leaves, by a food processor is fine. It saves so much time and it is definitely something I do. Do bear in mind that unless you chop everything very, very finely, the 'bits' can make holes in your paratha dough while you are rolling it out. When using a processor, you have to just chop it, not necessarily make it into a gooey paste!
"also I personally do not approve of the idea of putting all the vegetables together in a blender.they should all be chopped manually and finely to add to their individual flavours. " Why? Once you have added them all together (Onion, ginger, green chillies only, not potatoes), they are still going to be mixed to the mashed potato mix and their flavours will mingle. That is the idea, isn't it, to have all gentle flours mixed with the potato mash?
To end, I will say what I usually say; the recipes are there to give you ideas and 'know how'. One should feel free to adapt a recipe, as well as the method, to suit one's own taste, ways and convenience. So what I am saying to you Anjali is that if you prefer to do things the way you do them, that is absolutely fine, go for it and enjoy :-). And thank you for giving us an alternative way of doing things.
You can insist that YOU do not put coriander powder into your parathas, or even state that those in your family or local area do not do it either.
But rather than making sweeping statements, I would suggest that you try and remember that there are infinite number of variations of recipes across India and that many families and areas choose to do things differently.
They are not wrong just because they do not do things in your way.
No one is forcing you to follow a particular recipe, but it seems strange to me to try and insist that everyone else must do same as you do and must not cook according to their own tastes and preferences.
This website has been built initially to share our family recipes, as we make them, and then has grown to also share recipes from friends and also many of our readers.
We never suggest that our recipes are the only way of making anything, and indeed we always encourage people to tweak and adapt the recipes for their own tastes. What we offer is simply our recipes, our suggestions, our help, our advice to those who want it.
If the recipes here do not suit you or match your requirements, that is fine, no one is insisting you must change your cooking according to our website.
But I am not sure of the purpose of your post, here.