One of the biggest criticisms of PHP (aside from syntax) is the lack of any sort of scalar typing, weak, strong, doesn't really matter, it simply doesn't exist. A push in the right direction was the call for "scalar type hinting," which was laid out in this PHP RFC:
This topic, believe it or not, is a sensitive one, with some people being so against it that… well, I can't really think of an analogy, I don't know why the hell you'd be against it. Though some were against it just because they didn't like how this specific RFC defined how the PHP interpreter would know whether or not to do the actual type hinting.
Yes, they wanted to sink the idea because of a slightly related syntactical issue, instead of dealing with it later and implementing a very important thing.
The issue apparently caused so much grief that the major promoter, @AndreaFaulds has left PHP*:
This really sucks, and I find it to be truly disappointing. I think if we want to have PHP be taken more seriously by the broader programming world, we need to implement things that more "serious" languages have. I'm even more disappointed because I honestly thought that if this RFC did not pass, it may be years before anything close to type hinting on scalars is implemented in PHP, because it would create an untouchable issue like other things.
So, in the unlikelihood that other PHP developers are reading this, please keep pushing for scalar type hinting or something at least approaching that, and if you're a developer in PHP, keep asking for it, I know I will.
If no RFC is submitted for scalar typing in PHP 7, I'm probably going to switch languages, maybe Go or something, I don't know. I've been using PHP since 2002, and I've been waiting too damn long.
*Furthermore I think Andrea Faulds leaving PHP is sad because she promoted really good ideas and defined them very well in her RFCs. I think this is a language set back, but there are still a lot of great people on the PHP team, but I have to be honest and say I was really wanting to see all of her recent RFCs pass, they were all things I was also heavily interested in.