Does Bangladesh deserve the test status?
Undoubtedly YES. ICC will do well to get out of that incestuous club of theirs if they're really serious about spreading the game. The passion for the game in Bangladesh is unmatched even by the other south Asian nations and tbh, it is this passion of the subcontinental teams that will drive cricket, and for that matter ICC in the future. The ICC made a choice, a choice based on many parameters that will help spread the game and fill their coffers at the same time. So giving BD test status wasn't a favour to them, it's the other way round.
Is the Bangladeshi team improving?
Definitely YES. If you look at the current generation of players like Shakib, Tamim, Ashraful
, Razzaq, Mashrafe etc, they're are visibly better that their previous generations like Akram, Aminul or Rafique. There're already plenty of hints that the future generation (Nasir, Gazi, Mominul etc) will be even better than the current one. This is a clear indication that the team is evolving, the test series against SL showed what the team is really capable of, given the time and opportunities.
Is the team's progress a bit on the slower side?
Frustratingly YES. With a huge pool of talent to pick from, with top quality foreign coaches and support staff, with more than decent sponsors, state of the art sport's stadiums and facilities that had come up in the last 10 years, you might feel that the progress shown by the team is not up to its full potential. It'll not be ideal to compare it with the progress of the 40's India team since they had neither of the those mentioned above. The game was played by a few, and watched by even fewer. A Bangladeshi fan (or any cricket fan for that matter) has every right to believe that their team will be among the test's top 8 in 5-10 years time, and has every right to feel disappointed if it doesn't happen.
Is Bangladesh not getting enough help from the other boards?
Unfortunately YES. I could've said ICC, but in effect it is nothing but a common platform of the individual boards. A team improves by playing matches, and there is no substitute for match practice. In an ideal world the BD team had got full support of the other teams, but this is not an ideal world. Here you're on your own unless its economically viable to help, and in the current situation, it is not. One might argue that India, being a neighbour and the centre of world cricket, could have been more accommodating. But to expect such thing from BCCI is naive at least. Also what help is given to Ireland by ECB other than poaching it's players? How much help did NZ received from Australia in their early days? How much help was given to Zimbabwe by SA? (OK don't bother the last part).The truth is sports (be it football, cricket or Olympics) is no longer played in its original spirit and is turned into business, where if you're not generation profit, you're a liability.
Is the OP wrong in his assessment?
Just YES. Period.