Generic extractor bug

[ahmedtds]

Checklist

• I'm reporting a broken site support issue
• I've verified that I'm running youtube-dl version 2020.07.28
• I've checked that all provided URLs are alive and playable in a browser
• I've checked that all URLs and arguments with special characters are properly quoted or escaped
• I've searched the bugtracker for similar bug reports including closed ones
• I've read bugs section in FAQ

Verbose log

[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['-v', 'https://www.fox.com.tr/Ogretmen/bolum/1']
[debug] Encodings: locale cp1254, fs mbcs, out cp857, pref cp1254
[debug] youtube-dl version 2020.07.28
[debug] Python version 3.4.4 (CPython) - Windows-7-6.1.7601-SP1
[debug] exe versions: ffmpeg git-2020-07-30-134a48a, ffprobe git-2020-07-30-134a48a, phantomjs 2.1.1, rtmpdump 2.3
[debug] Proxy map: {}
[generic] 1: Requesting header
WARNING: Falling back on generic information extractor.
[generic] 1: Downloading webpage
[generic] 1: Extracting information
[download] Downloading playlist: FOX | Öğretmen 1. Bölüm
[generic] playlist FOX | Öğretmen 1. Bölüm: Collected 1 video ids (downloading 1 of them)
[download] Downloading video 1 of 1
[debug] Default format spec: bestvideo+bestaudio/best
[debug] Invoking downloader on "https://www.fox.com.tr/Ogretmen/bolum/'+videoSrc+'"
[download] Destination: FOX _ Öğretmen 1. Bölüm-1.unknown_video
[download] 100% of 140.33KiB in 00:01
[download] Finished downloading playlist: FOX | Öğretmen 1. Bölüm

Description

Note: This is not a site support request, already made site support request on this issue: #24395, this is a bug report because I think generic extractor shouldn't download a HTML file by thinking it's a video, instead it should say "unsupported URL"

As you can see from the log, generic extractor tries to download this URL as a video: https://www.fox.com.tr/Ogretmen/bolum/'+videoSrc+ and downloads the HTML file thinking it's a video.
This looked like a bug to me, instead it should just say "unsupported URL", not download HTML files, am I wrong?