On the same note you can use C and ignore all rules, coding using only void pointers and relying purely on gotos for flow control. :-)
Sure, and PHP is much closer to "C" (I intentionally use quotes because it's not matter of language but rather concept, but since you named it, I will keep this name) than to "Java" in this regard, it allows to do things that are more powerful - at cost of giving you the opportunity to shoot yourself in the foot. There are people who think PHP should be more "C" - like, have gotos, etc. - and there are people who think PHP should be more "Java" - like have strict signature enforcement or, God forbid, exception declarations. I personally think PHP is quite good the way it is. :)
On the other note, C and Java are static compiled languages, and PHP is dynamic language, which makes doing some things in PHP much easier than in C or Java. For example, functions with flexible signatures. So I think we should use it and not only try to restrict it.