Dear Abhi,
Shruti may also be right in her observation about your organisation and your colleagues. So, you have to make your decision very carefully after weighing all the pros & cons of leaving your present company.
However, if you are emotionally attached to your old company, you need not make any request. There are other ways also to make them ready to invite you back by winning their confidence. Just start interacting with the responsible people there by having casual visits to learn about their problems and lend your helping hand voluntarily (without any remuneration), so that they may feel the necessity to call you back and offer you respectable position. But, never disclose your views to them about existence of bad work culture in the present company. Otherwise, as said by Simhan, your position will be just like a beggar. You won't be able to command that respect, which you would have enjoyed earlier or may be expecting now, if you get job on your request. Moreover, they may offer even lesser salary that what you had already been getting from that company.