In my opinion, only the most elite (in all the wrong ways) people care how you build your app.

PHP has flaws, sure[1]. But unless you are working on the app itself (or again, you are horribly elitist) it does not matter.

What matters is that the app is good. If the app is good, it doesn’t matter that its done in PHP, what matters is that it works.

EDIT: I guess it also matters if you’re selfhosting the app.

[1] I think PHP is overhated. As a stateless language it lacks a lot of complex features (and thus, admittedly, might be questionable for a project as large and complex as kbin), it has some questionable design decisions, but it’s really not as bad as people make it out to be.