First of all railways is not the ONLY measure of development, having dedicated trains is a matter of demand, which if found would've been used by railways a long time ago.
Having many routes doesn't ensure that you'll get halt of all the trains and dedicated trains, example is Itarsi, Mathura (which have way more demand than JAUNPUR). It just gives you an advantage of preference which itself is based on demand.
I told you about Suhaildev express and Ghazipur Bandra Express having same quota for both Ghazipur and Jaunpur and you still...
more... want dedicated trains extended from Allahabad ?? Which ones ? Duronto or Prayagraj or Tulsi ? Do you even have an idea of demand of trains from that place ?
Which train do you want extended ? Explain specifically with valid points ( not big district, traditional place, 2 BJP MP's, etc.)