He can't defend and was a key member of the worst defence in the division last season. He only looked decent the few times he was played further forward. There is a core of people making up shoddy facts the last couple of days. Richardson, according to Wikipedia played twelve times last season, so in what way was he a Key member of the worst defence? I presume he was injured to have played so little, but regardless the point remains...you're making things up. If you consider that he also played further forwards then maybe he had ten games in defence last season? At a guess. All this doesn't give me much faith in your opinion, or that you're not just another one on a mission to moan about everything. We have no money. We need experience, so that's what we're getting.
Who's to say he's being signed as a left back anyway? Maybe he's Tonev's replacement in the squad? Or being signed as a wingback?
I think you need to check your facts before having a go at others.