The right wing press and other media have a vested interest in denigrating the BBC and its based on very, very little. The reason is quite simple they feel that if the BBC can be destroyed then they will benefit, in content, audience, finance and of course political balance.
The quality and variety of programming across the varied BBC platforms that criticism's are very hard to vouch as not biased.
Given the rabid ravings of the right seem to lurch further to extremism anyone not agreeing with them is labeled "lefty" when what we are talking about is balance.
The labeling as biased of course comes from the right wing press, and there followers, just join in with blind adherence, because as we can see their opinions come directly from this media, when they could infact, given the current technology, form their own opinions.
There are those who are actually on the left who would say the BBC has a right wing bias, this is based currently on the reporting, or none reporting, of the NHS "reforms".
Very little of the BBC's output is of a party political nature, so to say it has a bias either right or left is inaccurate, it is a national treasure, without which to set the standard, television, would be a sea of reality crap and "celebrity" inanities.
Be careful what you wish for, if goes, it won't come back.