Earlier quoted context omitted.
If number of users was equivalent to quality you would be correct. But it isn't. Under your argument, Wal-Mart is a purveyor of family heirlooms.
The number of users is not equivalent to quality. It's an indication of quality. As for quality... No, Wal-Mart isn't a purveyor of items with the qualities of being expensive, extremely limited, and old. Quality is a subjective word, defined by different aspects. Just as I can, with justification, define Apple as a purveyor of low-quality hardware, I can say equally it sells high-quality software.
- coherent
- non-verbose
- provide solid high-level abstractions
- safe
- have a solid standard library
- optionally, easy to get started with
Of all these qualities, PHP is geared toward "ease of access" with a sprinkling of non-verbosity, and fails mostly or totally in the other categories. Just like the popularity of the Millenium trilogy does not mean Stieg Larsson can write, the popularity of PHP is more an indication of its low barrier to entry (especially combined with widespread hosting support) than anything else.