Because Twitter has received investment on the promise of eventual profit.

A low / no growth model is only feasible if they don't have investors / shareholders bucking for returns at every decision point. Twitter, has made a deal with the devil in becoming a publicly traded company because at some point needs to show their stakeholders a path to profitability. Job cuts, cutting expenditure whilst hopefully maintaining profits, are a good way to demonstrate this.

If Twitter wants to become a public internet utility, like wikipedia, existing investors will demand something like a share buyback, how will Twitter afford this without a period of profitability?

Finding a sugar daddy to buy them out is one option but the recent sutors probably felt that twitter stock is overvalued, largely because of the lack of profits.