There are just so many planets in this game that I will not have the patience to scan all of them. The reason I'm asking is because I haven't been able to get all of the upgrades that I want because I don't really bother with scanning. It's way to tedious and boring for me to scan more than 2-3 planets before quitting. Am I missing out? Should I be launching more of them probes?

While it is not necessary to scan the entirety of every planet, I would at least visit every single one of them to ensure you see all the side quests. You will be alerted right away if there is an anomaly that can be scanned (which means you can land).

It's definitely to your benefit to scan.  I cannot stress that enough. 
 
And, I guess, if you want the best possible ending, you could be cutting yourself short by not scanning the planets. But you, by no means, need to scan every planet. Just focus on the ones with "Rich" or "Good" element ratings.

make sure you have all your ship research upgraded at least, dont know its necessary to scan planets for that, they are kind of expensive.

There are side missions or anomolies, which you will miss.

Oh, and I got to a point where I stopped scanning completely, and I still had all of the upgrades and such that I needed. I had the best possible ending one can get. 
 
So again, no, there is no need.

" @Sir_Ragnarok: @warxsnake: I have the cannon for my ship and I believe I have an armor upgrade for it. "