Although officially Allardyce left by mutual consent, it was quite clear that he was pushed rather than jumped.
Curbs told Sky Sports News, "You look at the Premier League now with eight managers gone in six months and that's a tough situation we're in.
"I know there's been a lot of pressure, but it did surprise me that something happened yesterday to Sam.
"Newcastle are mid-table, they don't look as though they're going to be involved in anything relegation-wise, and a couple of results could possibly push them into the top eight or top six if they have a good run-in.
"Eight managers in six or seven months is too much.
"The expectation levels of everybody is a big problem. People have got to be realistic."