Yeah I saw that pic yesterday as well. Bangladesh really hates us. They consider us a rival. Not sure why. India v Pakistan is a rivalry. Australia v England is a rivarly. India v Bangladesh is not, regardless of how terrific Bangladesh have been at times over the past year or so. It's unrelated to that. Not every team you face forms a rivalry ffs.
Yes this is very interesting and I have spoken to a few BD fans especially during their India games and based on what I have read on Cricinfo and online
There are a couple of factors behind this.
1) I think it dates back to the 2007 WC when apparently Mashrafe and a few other BD players were talking to their Indian counterparts before the start of the tournament and apparently the Indian players were talking about the next round as if they were already there. This really bothered the BD players and of course we know what happened next.
2) The other issue that bothers BD is the fact that India despite being a neighbour has never ever invited BD for a test series.
3) Indian Star Sports pissed off a lot of people last year with their mauka ads, but none were more pissed than the BD fans.
4) The infamous no ball that reprieved Rohit during the World Cup Quarter Final

Apparently a Pakistani Aleem Dar conspired with BCCI to keep BD out of the World Cup.
5) Navjot Sidhu apparently insulted BD by saying they don't belong at the highest level
6) In general BD fans feel that Indians don't offer BD the respect as a nation.
Now just a disclaimer: These are not my opinions so please don't come after me. I am just stating what I have gathered. I can't comment on the validity or truth of these claims.
My own personal take from all this is that BD fans (not all of course, AndyZaltsHair is one of the best members over here) in general tend to be super nationalistic as is apparent from a certain poster here and Athar Ali's commentary

When you wear your nationalism on your heart, anything and everything is going to appear as an insult to you. I am not saying that this is exclusive only to people from BD...but on CW for most part, we don't tend to attract those kinds of fans (other than a few exceptions of course

)
The other factor is also that a lot of the BD fans are new cricket fans that you find online (cricinfo/youtube comments section) in that they have started watching cricket maybe in the last 5 years when BD have shown some improvement. So the perspective that you gain from having watched a lot of cricket is missing there. So while I would be upset about a bad umpiring decision going against Pakistan costing them the game, I would get over it pretty soon because I won't take it personally..because I have watched enough cricket to know this is going to happen. But when you haven't watched that many games, especially those involving other teams as BD don't get to play as much, a wrong umpiring decision is going to be a major major thing for you and you will think it's a conspiracy against your team.