The problem is that talking about what they did during their tenure does not suit their agenda for the general elections.
The agenda is nationalism and apparently "Hindutva".
What everyone needs to understand is that being nationalist does not relieve you from the responsibilities of running a state/nation.
Having said that, they do not always shy away from questions about their rule (not all of them).
I would also like to talk about WB but think it's futile.
I agree but there are some good schemes which worked at ground level.
Mudra loan and gas connection worked . They can say that in next tenure they will tweak and make it more affordable but they are not.
WB is a burning pot only for for one simple reason. Eye for an Eye.
In south, BJP nationalist and divisive politics did not get traction cos people just ignored it and BJP cannot bark on a wall all time.
But in Bengal, Both TMC and Left have violence in their DNA, and so BJP started the same, they had to face the massive backlash in form of violence and its getting worse as days go by.
Too much of good is bad,mix some evil in it
people will not make the mistake of ignoring that, be it NDA, UPA or any other political outfit
You are again ignoring how it works in India. See what[^] happened yesterday, if you know the background of course.
By your comment, if people particularly in rural areas, hadn't ignored such things and voted ONLY for development, most of the current veterans would have been nowhere in the picture. And if the Congress do get in power in 2019 it will solely be because of the "72k promise", nothing else. And if you don't agree, do keep an eye on the results from rural constituencies on 23rd.
On a related note, there was a humorous tweet[^] I read a few days back. This is how it's working nowadays.
To add, it's not always BJP who dig out the past. When Modi said DRDO conducted an ASAT test, Rahul tweeted DRDO was founded in the Nehru era. When China blocked ban on Azher, Rahul said he was released by BJP in the first place. When Modi said India conducted surgical strikes, Congress again said we did that too in our times. There are many other examples as well.
To summarise, not just BJP, the Congress as well want to benefit from the past and keep on digging out their achievements and failures of BJP from the past.