There's always lots of PHP hating going on from language snobs, mostly from people with toy projects in the latest language du jour (was Ruby, then Node, Scala, now Clojure and Go).
They're not. The baseline probability of profitability for these types of companies is incredibly small. However, the potential profit that you might make for any one of these companies is extremely high (usually by selling the company, not by the company's inherent ability to turn a profit) - so invest in multiple companies and if you're lucky the 'big one' will beat your losses many times over.
From an engineering perspective you're probably correct. However, from a commercial perspective (be it long-term support, business continuity, cost of developers/support) PHP is one of the best solutions.