He had to take out a giant loan to afford the purchase (debt financing), which twitter needs to pay about $1B a year to service. Twitter wasn't getting anywhere near that in profit.
Twitter had like two profitable quarters in its existence and now on top of the usual operating costs they have to be profitable enough for 1 billion/year debt repayment.
If I'm being very generous, I'd give Twitter 6 more months.
Give Musk a chance… guy knows how to build and grow companies