He cut Twitter's expenses significantly while avoiding reliability issues (a feat that debunked several predictions by tech "experts" on HN about potential major outages) and while adding several new useful features. Admittedly, his decision to unban several controversial figures was debatable from a business standpoint, at least in the short term. However, this was not an oversight but a conscious decision, based on principles rather than profits.
Your impression is probably heavily biased by traditional media, who in general do not like him one bit.
Your impression is probably heavily biased by traditional media, who in general do not like him one bit.