You have a point. You can do a lot more with your computer than use it for a scope though.
Not sure what Fluke model you are referring to. Looking at the 190 series specs show that even the ADC 212/3 has some advantages.
The Fluke is an 8 bit scope and the 212/3 is a 12 bit scope. This means that the 212/3 has superior vertical resolution and accuracy.
Horizontally, the Fluke has a 1200 point record length per channel and the 212/3 shares a 32,000 point record length between the two channels. This provides more samples on a screen so that you have a more accurate reconstruction with much greater detail.
All instruments have different limitations. The Fluke has a much faster processor but that would only become an advantage at very short time bases. We use long time bases in automotive. The Fluke has a pulse width trigger too, that the 212/3 does not.
The hand held unit is more convenient but being PC based has some clear advantages as well. Storage and printing are a snap and you have a huge hard drive you can record screens to. Also, since each saved capture is also a preset, the number of presets is virtually unlimited. In addition, the large PC screen display makes viewing much more pleasant, especially for us older folks.