500carrots

No. You could give CGIs any filename, in any directory, on many shared hosting environments in the 90s. I know because I did it. Some shared hosting providers allowed persistent processes. Also, in the 90s, many small businesses self-hosted on tower PCs connected by fractional T1s. Many hobbyists self-hosted on dorm Ethernet (which had publically routed static IPs then) or got a corporate network administrator buddy to give them bootleg colocation.

PHP was successful because it was embedded in the HTML which lowered the barrier of entry. That's the only reason.